Evidence Law and the Jury:
A Reassessment
Lisa Dufraimont*
The common law of evidence is counterintuitive because
it seeks to facilitate the search for truth by regulating fact-
finders access to and evaluation of evidence. Since truth seems
most likely to emerge when adjudicators reason freely from all
available information, this puzzling strategy of seeking truth
through evidentiary regulation demands some explanation. The
orthodox explanation is that evidentiary regulation functions as
a form of judicial control over the jury. Because juries are
untrained, non-professional adjudicators, they are said to lack
the competence to evaluate evidence. On this view, evidence
rules are primarily directed at constraining jury decision
making and preventing jury error. This jury-centred view has
been criticized, and scholars have advanced other explanations
for truth-seeking evidence rules. Some suggest that evidence
law operates chiefly to promote the search for truth within the
context of the adversary system, while others contend that
evidence rules are primarily directed at managing the risk of
witness dishonesty.
This article examines the claim that evidence law
represents a form of jury control, and also considers some
competing explanations for evidence rules. The author argues
that no single principle explains the law of evidence. A
complex set of explanations is needed to account for the
historical origins of the rules and to justify them analytically.
Moreover, the salience of these various explanations can only
be
in particular doctrinal contexts. Jury-related
rationales are most persuasive where there are solid reasons to
believe that juries have trouble evaluating the particular form of
evidence at issue. Social-scientific research does not support
the conclusion
incompetent
adjudicators, but it does indicate that juries struggle with
specific types of evidence. Consequently, the question whether
a particular evidence rule can be justified on jury-control
grounds depends, first, on the specific competencies required to
evaluate the evidence and, second, on what is known about jury
psychology and behaviour.
juries are generally
judged
that
Le droit de la preuve en common law est contre-intuitif
puisquil prtend faciliter la recherche de la vrit. En raison de
la prsomption que la vrit se dvoile plus facilement lorsque
les juges sont libres de considrer toute information qui leur est
disponible, lencadrement de la preuve est une stratgie qui
demande tre explique. Lexplication orthodoxe de cette
rglementation est quelle constitue une forme de contrle
judiciaire du jury. Les jurs tant des juges non-professionels et
sans formation, il est pris pour acquis que ces individus nont pas
la comptence ncessaire pour valuer la preuve. Selon ce point
de vue, le droit de la preuve a la fonction de contraindre la
dlibration des jurs et dviter les erreurs qui pourraient
survenir. Cet accent mis sur le jury a dj t critiqu et plusieurs
auteurs avancent dautres explications pour lexistence de rgles
de preuve facilitant la recherche de la vrit. Certains suggrent
que le droit de la preuve existe afin de faciliter la recherche de la
vrit dans un systme adversarial, tandis que dautres proposent
que ces rgles tentent de contrebalancer la malhonntet
potentielle des tmoins.
Cet article examine la thorie voulant que le droit de la
preuve reprsente une forme de contrle du jury et considre des
explications alternatives pour lexistence des rgles dans ce
domaine. Lauteur soutient quun seul principe ne peut expliquer
le droit de la preuve. Un ensemble complexe dexplications est
requis afin dexprimer adquatement les origines historiques de
ces rgles et de les justifier de faon analytique. De plus,
limportance de chaque explication peut seulement tre
dtermine dans des contextes doctrinaux spcifiques. Les
explications ayant rapport au jury sont persuasives lorsquil y a
une raison solide de croire que les jurs auront de la difficult
valuer un type spcifique de preuve. Les recherches socio-
scientifiques entreprises sur le sujet ne soutiennent pas la thse
que les jurs sont gnralement incomptents. Consquemment,
la question de savoir si une rgle de preuve spcifique peut tre
justifie laide dune explication ayant rapport au contrle du
jury dpend, premirement, des comptences particulires
requises pour valuer la preuve en question et, deuximement,
sur ce qui est connu sur la psychologie et le comportement des
jurs.
* Assistant Professor, Queens University, Faculty of Law, LL.B. (Toronto), LL.M., J.S.D. (Yale).
This article is a revised version of the first chapter of my doctoral dissertation, The Problem of Jury
Error in Canadian Criminal Evidence Law, which was completed in December 2006 in fulfillment of
the requirements for the J.S.D. degree from Yale University. I gratefully acknowledge the institutional
support of Yale Law School and the Social Sciences and Humanities Research Council of Canada,
which funded the research with a Doctoral Fellowship. Special thanks are also due to my doctoral
supervisor, Steven Duke, and to others who read and offered valuable comments on this work,
including Mirjan Damaka, Abraham Goldstein, Kate Stith, and Don Stuart.
Lisa Dufraimont 2008
To be cited as: (2008) 53 McGill L.J. 199
Mode de rfrence : (2008) 53 R.D. McGill 199
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Introduction
I. The Evidence Law Puzzle
A. Truth and Other Policies
B. The Structure of Evidence Law
C. Common Law Ambivalence
II. The Jury Explanation
A. The System and its Justifications
1. Finding Facts
2. Tempering the Law on Behalf of the Community
3. Educating the Public and Legitimizing the System
B. Mistrust and Control
1. Three Risks
2. Jury-Control Strategies
3. The Tradition of Jury Control
C. Evidence Law as Jury Control
1. The Orthodoxy
2. Explanatory Power
3. The Competence Problem
a. Finding a Reference Point
b. General and Specific Competencies
III. Competing Explanations
A. The Adversary System
1. Features, Justifications, and Criticisms
2. Evidence Law as Advocate Control
a. Facilitating Adversary Testing
b. Restraining Adversarial Excess
B. Dishonesty
C. The Complex Picture
Conclusion
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Introduction
The common law of evidence is a puzzling creation.1 Although the modern
system of evidence law centred on exclusionary standards like the hearsay rule has
only existed for about three centuries, it appears to many observers as a relic of
obscure origins and questionable value.2 Continental lawyers find it difficult to
fathom,3 while even scholars within the common law tradition have called for its
abolition.4 Evidence law, of course, has its defenders, but it seems worthwhile to
investigate the doubts that surround the enterprise.
Much of this perplexity can be traced to a central and counterintuitive feature of
evidence law: it seeks to rationalize the search for truth by regulating the introduction
of proof at trial. Common sense suggests that accurate fact-finding is most likely to
result when adjudicators reason freely from all available relevant information. Instead
of ensuring free access to and permitting free evaluation of evidence, however,
evidence law comprises a set of exceptions to this freedom of proof.5 If asked to
envision an ideal method for ferreting out the truth about past events, few would
imagine a process encumbered by technicalities that conceal relevant information
from fact-finders and seek to control their evaluation of the evidence they are allowed
to see. But the law of evidence constitutes just such a set of encumbrances. And while
some pursue other policies, frequently the rules are directed at serving the search for
truth itself. Thus, evidence rules appear apt to impede the very fact-finding they are
designed to promote.
Why, then, does our law use evidence rules to advance the search for truth? The
classic explanation points to the common law jury, which, it is argued, lacks
competence to evaluate certain forms of proof. Unconstrained by evidentiary
regulation, it is feared that lay juries would produce an unacceptably high level of
1 For the purposes of this analysis, common law evidence denotes the system of evidence law in
force in common law jurisdictions, including its common law, statutory, and constitutional elements.
2 The hearsay rule and the three principal rules of criminal evidencethe corroboration,
confessions, and character rulesdeveloped primarily in the 18th century. See John H. Langbein, The
Origins of Adversary Criminal Trial (Oxford: Oxford University Press, 2003) at 179 [Langbein,
Origins]. See also J.M. Beattie, Crime and the Courts in England, 16601800 (Oxford: Clarendon
Press, 1986) at 363-76.
3 See Mirjan R. Damaka, Evidence Law Adrift (New Haven, Conn.: Yale University Press, 1997) at
4 The calls for the abolition of evidence rules from within the common law tradition are reviewed in
Alex Stein, The Refoundation of Evidence Law (1996) 9 Can. J.L. & Jur. 279 at 279-84. The most
celebrated of evidence laws abolitionist critics is 19th-century utilitarian and reformer Jeremy
Bentham, who advocated a natural system of procedure defined by the nonexistence of technical
rules (Rationale of Judicial Evidence, Specially applied to English Practice (London: Hunt and
Clarke, 1827) vol. 4 at 7-9).
5 See e.g. William Twining, Rethinking Evidence: Exploratory Essays, 2d ed. (Cambridge:
Cambridge University Press, 2006) at 192, 208-09 [Twining, Rethinking Evidence].
1-2.
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error in adjudication.6 The extent to which the jury in fact accounts for evidence law,
either historically or analytically, is a matter of ongoing debate.7 Other explanations
have been offered, the most promising of which focus on two other elements of a
common law trial: the adversary nature of the proceedings, and the ever-present risk
of witness dishonesty.8 Like the jury, these trial features are said to explain how the
search for historical truth can be facilitated rather than defeated by regulating
evidence.
This article is divided into three parts: the first will investigate what is so
puzzling about evidence law, the second will examine the jury-centred explanation of
this puzzle, and the third will consider alternative explanations. The discussion will
demonstrate that there is no unitary solution to the evidence law puzzle. The rules of
evidence are bound up with various features of the common law trial, including the
jury, the adversary system, and the possibility of witness dishonesty. The salience of
these justifications can only be judged in particular doctrinal contexts. Jury-related
rationales are most persuasive where there are solid reasons to believe that juries have
trouble evaluating the particular form of evidence at issue. The jury is not responsible
for all of evidence law, but it is a crucial part of the story.
I. The Evidence Law Puzzle
The rules of evidence are technical in character, which is to say that they depart
from everyday methods of determining the truth about past events.9 Nowhere is this
departure more marked than in those rules that regulate access to or evaluation of
evidence based on the theory that such regulation will lead to more accurate results.
This approach appears perverse, as it seems to impose limits which no one, layman
or scientist, in search for the truth would tolerate.10 For present purposes, this feature
of common law adjudication will be labelled the evidence law puzzle. The nature
of this puzzle will be fleshed out in this part.
6 See e.g. John H. Langbein, Historical Foundations of the Law of Evidence: A View from the
Ryder Sources (1996) 96 Colum. L. Rev. 1168 at 1194 [Langbein, Historical Foundations].
7 See e.g. Frederick Schauer, On the Supposed Jury-Dependence of Evidence Law (2006) 155 U.
Pa. L. Rev. 165.
8 See e.g. Dale A. Nance, The Best Evidence Principle (1988) 73 Iowa L. Rev. 227 [Nance, Best
Evidence] (advancing an adversary-system explanation); Edward J. Imwinkelried, The Worst
Evidence Principle: The Best Hypothesis as to the Logical Structure of Evidence Law (1992) 46 U.
Miami L. Rev. 1069 (positing an explanation centred on witness dishonesty).
9 See Damaka, Evidence Law Adrift, supra note 3 at 11-12.
10 Edmund Morris Morgan, Some Problems of Proof Under the Anglo-American System of
Litigation (New York: Columbia University Press, 1956) at 87 [Morgan, Problems of Proof].
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A. Truth and Other Policies
Truth finding holds pride of place among the objectives of formal adjudication,
and for obvious reasons.11 In general, if there were no dispute about what happened,
there would be no trial. Juries, and in their absence, judges, try the facts, and their
verdicts represent authoritative statements about past events.12 The rule of law itself
depends on accurate fact-finding, because justice according to law can only be
achieved when the rules of substantive law are applied to true facts.13 The search for
factual truth constitutes a necessary step in pursuit of the fundamental goal of legal
process: the enforcement of rights and obligations.14
Of course, truth finding is not the only goal of adjudication. Other important
values compete with the search for truth, so trial procedure is notand cannot be
maximally truth promoting.15 The legal system erects side constraints on truth finding
and contemplates that the search for truth may be sacrificed in any given case for the
protection of other policies.16 A classic example is attorney-client privilege, which
fosters lawyer-client relationships by shielding from view information that can be
necessary to accurate fact determination.17 In addition to protecting certain socially
valuable relationships, procedural rules pursue a wide variety of policies that
constrain the search for truth, including procedural efficiency and affordability, state
security, privacy, dignity, fairness, and due process.18
11 See e.g. R. v. Nikolovski, [1996] 3 S.C.R. 1197, 31 O.R. (3d) 480 ([t]he ultimate aim of any trial,
criminal or civil, must be to seek and to ascertain the truth at 1206, cited to S.C.R.).
12 See Charles Nesson, The Evidence or the Event? On Judicial Proof and the Acceptability of
Verdicts (1985) 98 Harv. L. Rev. 1357.
13 See e.g. Martin P. Golding, On the Adversary System and Justice in Richard Bronaugh, ed.,
Philosophical Law: Authority, Equality, Adjudications, Privacy (Westport, Conn.: Greenwood Press,
1978) 98 at 107.
14 See Bentham, supra note 4 at 477; Twining, Rethinking Evidence, supra note 5 at 199; William
Twining, Theories of Evidence: Bentham and Wigmore (London: Weidenfeld & Nicolson, 1985) at 16,
89 [Twining, Theories of Evidence]; David M. Paciocco, Truth and Proof: The Basics of the Law of
Evidence in a Guilt-Based System (2001) 6 Can. Crim. L. Rev. 71 at 74 [Paciocco, Truth and
Proof].
15 See Damaka, Evidence Law Adrift, supra note 3 at 121; Paul Roberts & Adrian Zuckerman,
Criminal Evidence (Oxford: Oxford University Press, 2004) at 3-4; Mirjan Damaka, Truth in
Adjudication (1998) 49 Hastings L.J. 289 at 301.
16 See Twining, Rethinking Evidence, supra note 5 at 199; Twining, Theories of Evidence, supra
note 14 at 89.
17 See R. v. Gruenke, [1991] 3 S.C.R. 263, 6 W.W.R. 673 [Gruenke cited to S.C.R.] ([t]he prima
facie protection for solicitor-client communications is based on the fact that the relationship and the
communications between solicitor and client are essential to the effective operation of the legal
system at 289).
18 See Twining, Theories of Evidence, supra note 14 at 14; D.J. Galligan, More Scepticism About
Scepticism, Book Review of Theories of Evidence: Bentham and Wigmore by W. Twining, (1988) 8
Oxford J. Legal Stud. 255; Jack B. Weinstein, Some Difficulties in Devising Rules for Determining
Truth in Judicial Trials (1966) 66 Colum. L. Rev. 223 at 241.
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B. The Structure of Evidence Law
Thus, truth and other policies form a complex of varied and sometimes
conflicting goals underlying trial procedure. These values and value conflicts find
expression in the structure of evidence law, which, broadly understood, comprises the
rules regulating the introduction of proof at trial. Historically, these rules developed
ad hoc in response to various perceived problems attending legal process.19
Consequently, evidence law reflects no systematic plan or coherent analytical
framework,20 but instead represents a set of disparate exceptions to a general norm of
free proof.21 This free-proof norm requires that juries, judges, and lawyers generally
be unfettered by technical rules that interfere with common-sense processes of
reasoning and fact-finding.22 Evidence law limits this freedom of proof by regulating
and restricting the fact-finders access to and evaluation of particular forms of
evidence.23
Admittedly, evidence scholarship typically focuses on the question of free access
to evidence, such that evidence law becomes identified with rules of exclusion.24
However, the common law has long included rules that, while not restricting access to
information, structure or limit the fact-finders free evaluation of evidence.25
Examples include the existing and historical rules requiring corroboration of or
cautionary jury instructions on certain types of evidence, as well as rules prohibiting
certain inferences and declaring some evidentiary items admissible only for limited
purposes.26 It would therefore be a mistake to understand evidence law simply as a
19 James Bradley Thayer, A Preliminary Treatise on Evidence at the Common Law (Boston: Little,
Brown, 1898) at 3-4; Twining, Theories of Evidence, supra note 14 at 1.
20 See e.g. Peter Murphy, Evidence, Proof, and Facts: An Introductory Essay in Peter Murphy, ed.,
Evidence, Proof, and Facts (Oxford: Oxford University Press, 2003) 1 at 2.
21 According to William Twining, pioneering 19th-century American evidence scholar James
Bradley Thayer treated the rules of evidence as a mixed group of exceptions to a principle of
freedom of proof … [N]early all modern writers on evidence in the common law would have accepted
some version of Thayers thesis (Rethinking Evidence, supra note 5 at 203).
22 Ibid. at 209.
23 See generally Mirjan Damaka, Free Proof and its Detractors (1995) 43 Am. J. Comp. L. 343;
Karl H. Kunert, Some Observations on the Origin and Structure of Evidence Rules Under the
Common Law System and the Civil Law System of Free Proof in the German Code of Criminal
Procedure (196667) 16 Buff. L. Rev. 122 at 123-24, 155; William Twining, Freedom of Proof and
the Reform of Criminal Evidence (1997) 31 Isr. L. Rev. 439 at 448-49.
24 See e.g. Murphy, supra note 20 at 2 ([t]he law is essentially exclusionary in nature). But see
Philip McNamara, The Canons of Evidence: Rules of Exclusion or Rules of Use? (1985) 10 Adel.
L.R. 341 at 347 (arguing that the so-called exclusionary rules of evidence are better understood as
rules of use that, in effect, limit the trier of facts deliberative freedom).
25 See Damaka, Evidence Law Adrift, supra note 3 at 18, 24.
26 Cautionary jury instructions are required, for example, whenever the prosecution relies on an
eyewitness identification that the defence claims is mistaken. See R. v. Haughton (2004), 187 O.A.C.
67 at para. 18, 62 W.C.B. (2d) 276 (C.A.) [Haughton]; infra note 160 and accompanying text. An
example of a rule making evidence admissible only for limited purposes is provided by the general
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2008]
body of exclusionary rules.27 To review, evidence rules limit freedom of proof by
restricting access to evidence, but also by structuring the fact-finders evidentiary
analysis; they reflect no unitary policy but rather pursue a variety of policies.
Evidence scholars have been challenged to impose order on this rather scattered set of
exceptions to freedom of proof.
Most agree that evidence doctrines are essentially of two kinds: intrinsic rules
directed at facilitating the pursuit of truth and extrinsic rules aimed at advancing
other policies.28 In John Henry Wigmores well-known formulation, extrinsic rules are
called the rules of extrinsic policy because they advance values and goals that lie
outside the basic rationalist project of adjudication.29 Privileges and rules excluding
illegally-obtained evidence are obvious examples.30 Wigmore called intrinsic rules the
rules of probative policy and separated them into two subcategories: relevancy
requirements and the rules of auxiliary probative policy.31 The two subcategories of
probative-policy rules are both concerned with matters internal to the truth-seeking
process. They ensure, respectively, that all evidence is minimally logically probative
of the factual question and that particularly misleading or unreliable forms of proof
potentially unreliable hearsay evidence, for exampleare not permitted to lead the
fact-finder astray.32 Since Wigmores formulation, the taxonomy has been simplified
and the essential distinction now recognized is between intrinsic and extrinsic rules,33
rule that when an accused testifies, criminal record evidence is admissible on the issue of the
accuseds credibility as a witness but not to show the accuseds propensity to commit the offence. See
R. v. Corbett, [1988] 1 S.C.R. 670, 85 N.R. 81 [Corbett cited to S.C.R.]; infra note 153 and
accompanying text.
27 See Twining, Rethinking Evidence, supra note 5 at 225-26.
28 The labels intrinsic and extrinsic are borrowed from Mirjan Damaka, who uses them to
distinguish between the two basic types of exclusionary rules (Evidence Law Adrift, supra note 3 at
12-17). In this analysis, the labels are used more inclusively and apply both to exclusionary rules and
to other kinds of evidentiary regulation.
29 Evidence in Trials at Common Law, rev. ed. by Peter Tillers (Boston: Little, Brown, 1983) vol. 1
at 689 [Wigmore, 1 Evidence] (stating that these rules pursue extrinsic policies that override the
policy of ascertaining the truth by all available means).
30 See e.g. Gruenke, supra note 17 at 286 (noting that communications covered by a class privilege
are excluded not because the evidence is not relevant, but rather because, there are overriding policy
reasons to exclude this relevant evidence); Canadian Charter of Rights and Freedoms, s. 24(2), Part I
of the Constitution Act, 1982, being Schedule B to the Canada Act 1982 (U.K.), c. 11 [Charter]
(providing for the exclusion of evidence obtained in violation of constitutional rights).
31 1 Evidence, supra note 29 at 688-89.
32 Ibid. See also R. v. Khelawon, 2006 SCC 57, [2006] 2 S.C.R. 787, 274 D.L.R. (4th) 385
[Khelawon] (upholding the general rule that hearsay is inadmissible on reliability grounds).
33 For different versions of this taxonomy, see Damaka, Evidence Law Adrift, supra note 3 at 12-
17; Galligan, supra note 18 at 255; Paciocco, Truth and Proof, supra note 14 at 90-92. The
distinction between intrinsic and extrinsic rules is complicated by the fact that truth-related and non-
truth-related objectives can be difficult to differentiate. Some rules of evidence hamper the search for
truth in individual cases, but are nonetheless claimed to be truth-promoting because their enforcement
over time tends to produce more truthful outcomes in adjudication. See e.g. ibid. at 77. Attorney
client privilege, for example, can lead to the exclusion of important information in individual cases,
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between doctrines ensuring the rationality of proof and those reflecting a conflict
of values.34
Ultimately, what is puzzling about the law of evidence is its intrinsic
orientationits truth-seeking quality. There is nothing mysterious about extrinsic
rules, which simply allow the search for truth to be trumped in some cases by other
pressing goals and values. Intrinsic rules, on the other hand, appear self-defeating.
Restricting access to and evaluation of evidence seems likely to decrease, rather than
increase, rationality in adjudication. Yet intrinsic rules make up the core of common
law evidentiary regulation and are widely recognized as one of its distinctive
features.35 It therefore seems necessary to seek justifications for these intrinsic rules.
C. Common Law Ambivalence
The common law reflects an ambivalent attitude toward evidence. On the one
hand, it is generally agreed that evidence and reason are the twin bases of any rational
conclusion about past events.36 Completeness of evidence is a scientific ideal that has
become widely accepted as a means of reliably finding facts.37 Fact-finders are
therefore generally expected to reach the most accurate conclusions when they have
access to and the freedom to reason from all the relevant evidence.38 On the other
hand, the common law contemplates the possibility that the very evidence that is
relevant to the verdict also misleads the fact-finder. Certain forms of proof, while
relevant, are thought to put the accuracy of fact-finding in jeopardy:
but is thought to facilitate truth-finding on a systemic level by encouraging clients to be open with
their lawyers. See e.g. Damaka, Truth in Adjudication, supra note 15 at 307. Further muddying the
distinction between intrinsic and extrinsic evidence rules is the reality that evidence rules often
straddle both kinds of goals. The inadmissibility of coerced confessions, which is founded on the dual
concerns that such confessions are both unreliable and the products of official mistreatment, probably
constitutes the best example (Damaka, Truth in Adjudication, supra note 15 at 306-07).
34 Galligan, supra note 18 at 255.
35 See e.g. Damaka, Evidence Law Adrift, supra note 3 at 14, 24; John Henry Wigmore, Evidence
in Trials at Common Law, rev. ed. by James H. Chadbourn (Boston: Little, Brown, 1972) vol. 4 at 396
[Wigmore, 4 Evidence]; Glanville Williams, The Proof of Guilt: A Study of the English Criminal Trial,
3d ed. (London: Stevens & Sons, 1963) at 195ff.; Stein, supra note 4 at 282.
36 By definition, rational adjudication seeks truth through reason on the basis of evidence. See e.g.
Jerome Frank, Courts on Trial: Myth and Reality in American Justice (Princeton, N.J.: Princeton
University Press, 1950) at 80 (arguing that a rational trial process requires an intelligent inquiry
based on all the evidence and directed at finding the truth).
37 John D. Jackson, Theories of Truth Finding in Criminal Procedure: An Evolutionary Approach
(1988) 10 Cardozo L. Rev. 475 at 504 (discussing evidentiary completeness as an ideal[] of the
scientific method).
38 See e.g. Murphy, supra note 20 at 2; Richard D. Friedman, Truth and Its Rivals in the Law of
Hearsay and Confrontation (1998) 49 Hastings L.J. 545 at 557. But see Stein, supra note 4 at 287-89
(arguing that giving fact-finders more information of uncertain value will not necessarily increase
fact-finding accuracy).
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The desirable end to be attained by the admission of every species of evidence,
may be more than counterbalanced, in some instances, by the evil attending it;
sometimes, in the shape of inconvenience and expense inseparable from its
procurement; sometimes, from the danger of error arising from the deceptive
nature of the evidence itself.39
Put simply, the common law has always assumed that relevant evidencethe very
heart of rational adjudicationsometimes poses a danger to accurate fact
determination.
This assumption frequently takes the form of a fear that adjudicators are apt to
misuse or overvalue certain forms of evidence. The apprehension that particular types
of relevant information are vulnerable to misuse or overvaluation is emblematic of
common law evidence, and it underpins the intrinsic rules so typical of that body of
law.40 The common law anxiety about the potential misuse of relevant evidence is
built on a complex agglomeration of concerns about unreliability and prejudice. The
two principal perceived dangers are, first, that adjudicators may be led into error by
evidence that is less reliable than it appears, and second, that certain forms of
evidence invite unfair prejudgment.41 Rules respecting hearsay, accomplice testimony,
and bad character evidence, to name but a few, are driven largely by the concern that
certain forms of relevant evidence may lead adjudicators astray: unreliability is the
chief danger associated with hearsay and accomplice testimony, while bad character
evidence is primarily feared to be prejudicial.42 Consciousness of these two dangers
has given rise to numerous evidence rules.
From the perspective of common lawyers, then, evidence appears as a double-
edged sword. They recognize that evidence is the basis of rational fact-finding, but
they are also keenly aware of the possibility that certain forms of proof may be
unreliable or prejudicial and may, as a result, endanger fact-finding accuracy. But
where does this attitude come from? What lies at the root of this suspicion? Some
understanding of why relevant evidence poses a danger to accurate fact-finding
some theory of erroris required.
39 Edward Livingston, Introductory Report to the Code of Evidence in The Complete Works of
Edward Livingston on Criminal Jurisprudence (New York: National Prison Association of the United
States of America, 1873) vol. 1 at 421.
40 See e.g. Damaka, Evidence Law Adrift, supra note 3 at 24.
41 Ibid. at 14-15; Williams, supra note 35 at 195 (noting the common law tendency to exclude
evidence regarded as unfair, or as dangerously misleading); Stein, supra note 4 at 294 (labelling the
dangers of unreliability and prejudice as risk of overvaluation and verdicts ad hominem,
respectively). See also Paciocco, Truth and Proof, supra note 14 at 95-96 (observing that the classic
manifestation of prejudice in criminal law is unfair prejudgment of the case against an accused).
42 On the reliability problems with hearsay evidence and accomplice testimony, see Khelawon,
supra note 32 (hearsay); R. v. Vetrovec, [1982] 1 S.C.R. 811, 136 D.L.R. (3d) 89 [Vetrovec cited to
S.C.R.] (testimony of unsavoury witnesses, including accomplices). On the prejudicial effect of bad
character evidence against the accused, see R. v. B. (C.R.), [1990] 1 S.C.R. 717 at 744, 109 A.R. 81
[B.(C.R.) cited to S.C.R.].
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II. The Jury Explanation
Traditionally, common lawyers have explained the dangers associated with
unreliable and prejudicial evidence by reference to the jury system. Juries, as groups
of laypersons, are said to lack competence to assess evidence and find facts.43 The
need to compensate for the adjudicative incompetence of these untrained,
nonprofessional decision makers has been the standard explanation for the origin and
continuing justification of evidentiary rules. Put simply, evidence law is classically
understood as a form of judicial control over the jury. This view of the relationship
between evidence law and the jury will be investigated in the pages that follow. After
a brief description of the jury system and its justifications, the enduring patterns of
jury mistrust and control within the common law tradition will be explored. Next, the
focus will narrow to evidence law as jury control, with special attention paid to the
ways in which evidence rules compensate for weaknesses in jury fact-finding.
A. The System and its Justifications
Trial juries are panels of ordinary people, chosen more or less at random, and
called upon to adjudicate legal controversies arising in their local communities. Juries
and their members are supposed to be impartial adjudicators, representative of the
wider community of which they and the parties to the adjudication both form a part.44
Fundamentally, the jury is a lay institution: juries deliberate and make decisions
together, outside the immediate supervision and control of professional judges.45 In a
trial, the jury plays the role of the trier of fact, though its duties include not only
finding the material facts but also applying the pertinent rules of law as explained by
the judge. Juries are bound to decide the case only on the basis of the admissible
evidence presented to them during the trial.46 Historically in England, juries consisted
of twelve members and their verdicts were required to be unanimous,47 features that
have been retained in some systems but modified in others.48 Typically, the jury
43 See e.g. Thayer, supra note 19 at 2. See also Part II.C.1.
44 See e.g. R. v. Sherratt, [1991] 1 S.C.R. 509 at 523-25, 3 C.R. (4th) 129 [Sherratt cited to S.C.R.].
45 This feature sets common law juries apart from continental European forms of lay participation,
which generally require lay assessors and professional judges to deliberate together. See Mirjan R.
Damaka, The Faces of Justice and State Authority: A Comparative Approach to the Legal Process
(New Haven, Conn.: Yale University Press, 1986) at 36; John H. Langbein, Mixed Court and Jury
Court: Could the Continental Alternative Fill the American Need? [1981] American Bar Foundation
Research Journal 195 at 205 [Langbein, Mixed Court].
46 See e.g. R. v. G.(R.M.), [1996] 3 S.C.R. 362 at para. 15, 139 D.L.R. (4th) 193 [G.(R.M.) cited to
47 See J.H. Baker, An Introduction to English Legal History, 4th ed. (London: Butterworths, 2002) at
S.C.R.].
73, 76.
48 In Canada, criminal juries have twelve members and must give their verdicts unanimously. The
Supreme Court of the United States has held that, under the Constitution of the United States, criminal
juries may have as few as six members and 102 majority verdicts are permissible. See Williams v.
Florida, 399 U.S. 78 (1970); Ballew v. Georgia, 435 U.S. 223 (1978); Apodaca v. Oregon, 406 U.S.
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returns a general verdict as to guilt or liability, and may also have a role in deciding
the legal consequences that flow from the verdictthe amount of damages, the
length of the term of imprisonment, or the like.49 Juries deliberate in secret;50 they are
not required to give reasons for and are not accountable for their decisions in any
way.51 A jurys verdict, once delivered, can be difficult if not impossible to overturn,
particularly on grounds of factual error.52
Although the jury system remains in place in Canada, the United States and many
other parts of the world, the jury is in decline. Formal trials of all kinds have become
rarer over time, and this broad historical trend is most obvious in the area of jury
trial.53 Civil jury trials have all but vanished except in Canada and the United States.54
The criminal jury has proven more tenacious, but even in criminal cases, jury trials
are everywhere the exception.55 Yet jury trials nonetheless retain a systemic
404 (1972). However, most American jurisdictions require unanimous, twelve-person criminal juries
(Nancy Jean King, The American Criminal Jury (1999) 62:2 Law and Contemp. Probs. 41 at 46).
Juries in England and Wales are empanelled with twelve members, but they may deliver majority
verdicts (Sally Lloyd-Bostock & Cheryl Thomas, Decline of the Little Parliament: Juries and Jury
Reform in England and Wales (1999) 62:2 Law & Contemp. Probs. 7 at 20, 36).
49 Canadian criminal juries ordinarily offer only a general verdict on the issue of guilt, but
occasionally they make non-binding sentencing recommendations. Pursuant to s. 745.2 of the
Criminal Code, a jury that convicts a defendant of second degree murder should be asked whether it
wishes to make a recommendation on the period of parole ineligibility to be imposed (R.S.C. 1985, c.
C-46).
50 Jury secrecy is protected in perpetuity by s. 649 of Canadas Criminal Code (ibid.), which makes
it an offence to disclose the content of deliberations. Similar secrecy provisions apply in England and
Wales, but not in the United States. See Lloyd-Bostock & Thomas, supra note 48 at 11-12; King,
supra note 48 at 63 (arguing that U.S. free-speech protections are one explanation for the lack of
American jury-secrecy rules).
51 See R. v. Morgentaler, [1988] 1 S.C.R. 30, 44 D.L.R. (4th) 385 [Morgentaler cited to S.C.R.]
([t]he jury is never called upon to explain the reasons which lie behind a verdict at 78).
52 In Canada, only an unreasonable jury conviction can be set aside on grounds of factual error. See
R. v. Yebes, [1987] 2 S.C.R. 168, 43 D.L.R. (4th) 424; R. v. Binaris, 2000 SCC 15 at para. 24, [2000] 1
S.C.R. 381, 184 D.L.R. (4th) 193.
53 See infra notes 54, 55, 246, 247, and accompanying text.
54 Neil Vidmar, Foreword: The Common Law Jury (1999) 62:2 Law & Contemp. Probs. 1 at 1-2.
55 There are approximately 4000-5000 jury trials in Canada every year, accounting for less than 1
per cent of Canadian criminal cases (G. Ferguson, Community Participation in Criminal Jury Trials
and Restorative Justice Programs (2001) at 40, 42 [unpublished, archived with author]). By contrast,
a guilty plea is the outcome in roughly 70-90 per cent of Canadian criminal cases (ibid. at 24). The
great majority of Canadian criminal trials are tried by a judge sitting alone (Neil Vidmar, The
Canadian Criminal Jury: Searching For a Middle Ground (1999) 62:2 Law & Contemp. Probs. 141 at
147). American jurisdictions make much more extensive use of jury trial, and there are more than
150,000 such trials in the United States every year. See Dennis J. Devine et al., Jury Decision
Making: 45 Years of Empirical Research on Deliberating Groups (2001) 7 Psychol. Pub. Poly & L.
622 at 622. See also Neil Vidmar, A Historical and Comparative Perspective on the Common Law
Jury in Neil Vidmar, ed., World Jury Systems (Oxford: Oxford University Press, 2000) 1 at 7-11
(discussing the comparative strength of the jury system in the United States). Yet, the vast majority of
American criminal cases are resolved through plea bargaining and never go to trial, while many of the
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importance that belies their numbers because many of the most serious and important
criminal cases are tried by juries.56 The gravest offences in Canadas Criminal Code,
notably murder and treason, are normally required to be tried by juries.57 Jury trial is
also protected as a fundamental right of the accused in Canada and many other
jurisdictions.58
Defenders of the jury system argue that it fulfills several functions that, alone or
in combination, justify its continued existence. The jury is said to find facts
accurately, to dispense justice in a way that reflects community values, to protect
individuals against oppressive laws and law enforcement, to educate the public about
the justice system, and to legitimize that system in the public eye.59 Each of these
justifications for the jury system will be examined in turn.
1. Finding Facts
On the face of it, juries exist primarily to find facts, and many justify the use of
juries on the basis that they perform this task particularly well. The question whether
juries are in fact skilled fact-finders is controversial and will be discussed below, but
it is worth noting at the outset that claims that juries excel at accurate fact-finding are
normally based on the perceived strengths of non-professional, group decision
making. Group deliberation is thought to encourage a thorough consideration of
trials that do occur are bench trials presided over by a single judge (King, supra note 50 at 59).
Similarly, only about 1 or 2 per cent of criminal trials in England and Wales are tried by jury (Lloyd-
Bostock & Thomas, supra note 48 at 15).
56 However rare jury trials may be in the general run of criminal cases, of the more serious cases
that do go to trial, jury trials are a common mode of trial (Ferguson, supra note 55 at 42).
57 The short list of the most serious indictable offences also includes alarming Her Majesty and
inciting to mutiny; all these offences must be tried by jury unless both the accused and the Attorney
General of Canada consent to a trial by judge alone (Criminal Code, supra note 49, ss. 469, 471, 473).
Many other serious offences can be tried by jury at the option of the accused (ibid., ss. 536-36.1).
58 The right to a criminal jury trial is mentioned in two places in the Constitution of the United States
and was constitutionally enshrined in Canada in 1982. See U.S. Const. art. III, 2, cl. 3; ibid., amend.
VI; Charter, supra note 30, s. 11(f) ([a]ny person charged with an offence has the right … to the
benefit of trial by jury where the maximum punishment for the offence is imprisonment for five years
or a more severe punishment).
59 This catalogue of justifications emerges from the Canadian legal literature. See e.g. Law Reform
Commission of Canada, The Jury in Criminal Trials, Working Paper 27 (Ottawa: Minister of Supply
and Services Canada, 1980) at 5-17; Law Reform Commission of Canada, The Jury, Report 16
(Ottawa: Minister of Supply and Services Canada, 1982) at 5; Sherratt, supra note 44 at 523-24;
Ferguson, supra note 55 at 35. Analogous functions have been attributed to the jury by commentators
in other common law jurisdictions. See e.g. Neil Vidmar, A Historical and Comparative Perspective
On the Common Law Jury in Neil Vidmar, ed., World Jury Systems (Oxford: Oxford University
Press, 2000) 1 at 2 [Vidmar, Common Law Jury]; Benjamin Kaplan, Trial by Jury in Harold J.
Berman, ed., Talks on American Law, rev. ed. (Washington, D.C.: Voice of America, 1972) 51 at 53-
55, 57.
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issues and lead to more accurate verdicts.60 The proven advantage of collective recall
means that juries as groups remember significantly more evidence than would any
given individual.61 And since jurors are lay people, their diverse knowledge and life
experience enrich deliberations and help the jury interpret the import and weight of
evidence.62 Finally, because notwithstanding jury-selection rules it appears impossible
to find twelve jurors with no pre-existing attitudes or opinions, jurors diverse
preconceptions and biases are expected to cancel each other out in the jury room.63 In
sum, juries are imagined to be accurate fact-finders primarily because they function as
groups and contain people from all walks of life; they draw on a diversity of
experience and opinion, and a collective memory of the evidence to which no
individual decision maker could have access.
2. Tempering the Law on Behalf of the Community
The claim that juries make excellent adjudicators is often advanced, but it has
never been the sole or even the primary justification for the jury system, which is
prized first and foremost as a political institution. Indeed, even if it could be shown
that individual judges outperform juries as fact-finders, the jury system might well be
retained on the basis of its political justifications. Juries serve a number of purposes
that are broadly political, including the related functions of protecting individuals
against state oppression and meting out legal justice in a way that conforms to
community values. These twin functions depend on juries power to moderate, or
even ignore, the law.64
Because juries apply legal standards and deliver general verdicts without reasons,
they have the freedom to apply the law flexibly, in a way that responds to the equities
of the case and reflects community standards of fairness and justice.65 Just as courts of
equity historically granted relief where strict application of the common law would
have worked an injustice, juries infuse the communitys values into their decisions by
flexibly applying even those legal standards they recognize as valid and just. A jury
tried to moderate the law in this way in the celebrated case of R. v. Latimer,66 which
involved a father who killed his severely disabled daughter with carbon monoxide
60 See e.g. Randolph N. Jonakait, The American Jury System (New Haven, Conn.: Yale University
Press, 2003) at 42-51; The Jury in Criminal Trials, ibid. at 6-7. See also G.(R.M.), supra note 46 (the
great strength and virtue of the jury system [is] that members of the community have indeed come
together and reasoned together in order to reach their unanimous verdict at para. 14).
61 See Reid Hastie, Steven D. Penrod & Nancy Pennington, Inside the Jury (Cambridge, Mass.:
Harvard University Press, 1983) at 81, 230.
62 See Jonakait, supra note 60 at 44-46.
63 See e.g. R. v. Find, 2001 SCC 32, [2001] 1 S.C.R. 863 at para. 107, 199 D.L.R. (4th) 193 [Find]
(noting that group deliberations have diffusive effects).
64 See e.g. Weinstein, supra note 18 at 238.
65 The Jury in Criminal Trials, supra note 59 at 8-10 (calling the jury the [C]onscience of the
[C]ommunity).
66 (16 November 1994), (Sask. Q.B.), affd (1995), 126 D.L.R. (4th) 203, 134 Sask. R. 1 (C.A.).
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from his truck in order to save her from further pain, seizures, and surgery. Although a
more planned and deliberate murder is hard to imagine, the jury at Robert Latimers
first trial convicted him of second degree murder rather than the first degree murder
with which he was charged.67 When improprieties in the jury-selection process
necessitated a second trial,68 Latimer was convicted again, but the second jury
recommended to the judge that Latimer serve only one year in prison before
becoming eligible for parole,69 instead of the legally mandated ten-year minimum for
second degree murder. Although its attempt was ultimately unsuccessfulLatimer is
now serving life in prison without possibility of parole for ten years70it appears that
the jury tried to moderate the sentencing requirements in circumstances where many
in the community viewed the law as working an overly harsh result. Thus, even when
a law (such as the law of murder) generally accords with the communitys conscience,
juries have a role in softening its application to achieve individualized justice.
In other cases, a jurys refusal to apply the law strictly can amount to a more
radical defiance of legal commands. Juries have the power to nullify laws by
refusing outright to convict accused persons who they are convinced are factually
guilty,71 and there are many historical examples of such defiant acquittals by juries
who refused to enforce laws that they saw as unjust, oppressive, or otherwise
illegitimate.72 Hence, another recognized function of the jury is to protect individuals
from oppressive or unjust laws and law enforcement.73 The best-known Canadian
example of jury nullification is the case of Henry Morgentaler, a doctor who in
67 See Criminal Code, supra note 49, s. 231(2) ([m]urder is first degree murder when it is planned
and deliberate).
68 See R. v. Latimer, [1997] 1 S.C.R. 217, 142 D.L.R. (4th) 577.
69 R. v. Latimer (5 November 1997), (Sask. Q.B.).
70 Evidently swayed by the jurys sense of justice, the judge presiding over the second trial relied on
the dissenting reasons of Bayda C.J.A. in the appeal from Latimers first conviction (supra note 66)
and granted Latimer a constitutional exemption from the minimum period of parole ineligibility (R. v.
Latimer (1997), [1998] 12 C.R. (5th) 112, [1998] 121 C.C.C. (3d) 326 (Sask. C.A.)). The trial judge
held that, in these circumstances, to sentence Latimer to a ten-year period of parole ineligibility would
amount to cruel and unusual treatment or punishment contrary to s. 12 of the Charter (supra note
30). A unanimous Saskatchewan Court of Appeal rejected this constitutional-exemption argument and
imposed the mandatory minimum sentence of life imprisonment without possibility of parole for ten
years (R. v. Latimer (1998), [1999] 131 C.C.C. (3d) 191, [1999] 6 W.W.R. 118), and that sentence was
later upheld by the Supreme Court of Canada (R. v. Latimer, 2001 SCC 1, [2001] 1 S.C.R. 3, 193
D.L.R. (4th) 577).
71 The jurys nullification power was acknowledged recently by the Supreme Court of Canada in R.
v. Krieger, 2006 SCC 47, [2006] 2 S.C.R. 501, 272 D.L.R. (4th) 410 [Krieger] (under the system of
justice we have inherited from England juries are not entitled as a matter of right to refuse to apply the
law but they do have the power to do so when their consciences permit of no other course at para.
27, emphasis in original). See also Paul Butler, Racially Based Jury Nullification: Black Power in the
Criminal Justice System (1995) 105 Yale L.J. 677 at 700.
72 See King, supra note 50 at 50-51; Lloyd-Bostock & Thomas, supra note 48 at 9-10. For historical
examples of jury nullification, see infra notes 83-88 and accompanying text.
73 See e.g. Jonakait, supra note 60 at 25, 27; The Jury in Criminal Trials, supra note 59 at 11.
L. DUFRAIMONT EVIDENCE LAW AND THE JURY
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flagrant violation of the existing law operated free-standing abortion clinics in
Quebec and Ontario in the 1970s and 1980s, and was on several occasions acquitted
of abortion offences by Canadian juries.74 The Morgentaler juries were not
responding to the equities of the individual case; instead, by refusing to convict, they
repudiated the criminal prohibition itself. By the time the Supreme Court of Canada
struck down the abortion laws under the Charter, the Canadian jury had already
spoken on the validity of those laws in the eyes of the community.75
213
3. Educating the Public and Legitimizing the System
The final two functions of the jury systemeducation and legitimizationrelate
to the jurys political role as a site for public participation.76 Jury service provides
members of the public with an opportunity to participate directly in the administration
of justice, and therefore to learn about the operation of a system with which they
might otherwise have little contact.77 In addition to educating the community about
the justice system, the jury bolsters the legitimacy of that system in the public eye.
The community can be expected to have confidence in those judicial decisions its
own representatives have made.78 And indeed, there is evidence to suggest that in
Canada and elsewhere, the public broadly supports the jury system and places great
confidence in jury verdicts.79
B. Mistrust and Control
Curiously, the same features that are thought to justify the jurys existence also
ground an abiding mistrust of the institution. The lay character of the jury legitimizes
judicial decisions and provides an opportunity for community values to influence the
administration of justice, but it also raises concerns about the inexperience and
possible incompetence of juries as fact-finders. Inscrutable general verdicts empower
juries to ignore the law for purposes both noble and base. The limited reviewability of
their verdicts gives juries the freedom to apply the law in a way that reflects the
conscience of the community, even as it hampers appellate courts in their efforts to
control and correct fact-finding errors. The potential for jury nullification, the lack of
accountability, the absence of reasons, and the secrecy of deliberations strengthen the
74 See Don Stuart, Canadian Criminal Law, 5th ed. (Scarborough, On.: Thomson Carswell, 2007) at
539-42; Bruce Wardhaugh, Socratic Civil Disobedience: Some Reflections on Morgentaler (1989) 2
Can. J.L. & Jur. 91 at 102-06.
75 In Morgentaler (supra note 51), the abortion laws were struck down as violative of womens right
to security of the person protected under s. 7 of the Charter (supra note 30).
76 See generally Ferguson, supra note 55.
77 See e.g. ibid. at 35; The Jury in Criminal Trials, supra note 59 at 13.
78 See Ferguson, ibid.
79 See e.g. The Jury in Criminal Trials, supra note 59 at 2, 15-16 (reporting survey research on the
Canadian publics views of the criminal jury); Christopher Granger, The Criminal Jury Trial in
Canada, 2d ed. (Scarborough, Ont.: Carswell, 1996) at 29; Jonakait, supra note 60 at 22.
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jury in its political role, but they also smack of arbitrariness.80 According to legal
historian and jury critic John Langbein:
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Despite its merits, jury trial has always been fraught with danger. Jurors are
untrained in the law, they decide without giving reasons, they have no
continuing responsibility for the consequences of their decisions, and their
verdicts are quite difficult to review. The risks of error and partiality in this
system of adjudication are ineradicable.81
1. Three Risks
At bottom, the worry is that juries are prone to make wrong decisions. To decide
a case correctly, a jury must render a verdict that reflects true facts and conforms to
the applicable law, and it must reach that verdict not by hazard or on the basis of
impermissible preconceptions, but on the basis of the evidence. Thus, doubts about the
reliability of jury decision making are based on three distinct dangers: bias,
lawlessness, and adjudicative incompetence. First, the ability to judge cases impartially
may be compromised by individuals who bring their pre-existing biases into the jury
room. Verdicts may be distorted by racist jurors, for example, or by those who have
prejudged the accused guilty on the basis of negative pretrial publicity.82 Whether or
not the resulting verdict is factually and legally correct, a jury whose decision-making
process is tainted by bias fails in its adjudicative task.
Second, the rule of law may be undermined by juries that fail to apply the law or
that apply it inconsistently. Juries nullification power can be exercised in a morally
reprehensible fashion, as evidenced by the notorious historical tendency of white
juries in the southern United States to refuse to convict whites who did violence to
blacks, even as they convicted blacks whose factual guilt was very much in doubt.83
Experience has shown that the power to ignore the law becomes a pernicious form of
lawlessness when it is used to circumvent equal justice. Moreover, strictly speaking,
jury nullification runs counter to the rule of law even in cases where it is used for
some high-minded purpose,84 as when juries have nullified to protect religious
minorities from persecution,85 shield whistle-blowers from punishment,86 and free
80 See e.g. Franklin Strier, Reconstructing Justice: An Agenda for Trial Reform (Westport, Conn.:
Quorum Books, 1994) at 61-62.
81 Historical Foundations, supra note 6 at 1194. See also Langbein, Origins, supra note 2 at 321.
82 The risks of bias of these two kinds is well recognized in both Canada and the United States. See
e.g. R. v. Parks (1993), 15 O.R. (3d) 324, 65 O.A.C. 122 (C.A.) [Parks] (bias against black accused);
R. v. Williams, [1998] 1 S.C.R 1128, 159 D.L.R. (4th) 493 (bias against aboriginal accused) [Williams
cited to S.C.R.]; Sherratt, supra note 44 (pretrial publicity). See also David M. Tanovich, David M.
Paciocco & Steven Skurka, Jury Selection in Criminal Trials: Skills, Science, and the Law (Concord,
Ont.: Irwin Law, 1997) at 106-17; King, supra note 50 at 53-59.
83 See e.g. Weinstein, supra note 18 at 237-39.
84 Butler, supra note 71 at 706.
85 Bushells Case (1670), the most celebrated single case of jury nullification, appears to be an
example of a jury nullifying the law in order to protect members of a religious minority (Vaugh. 135,
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those who helped black slaves to escape.87 Insofar as the laws that were sought to be
enforced in such cases were morally wrong, most would agree that it was desirable
for juries to act outside the law.88 However, nullification undeniably raises the spectre
of jury lawlessness. Finally, quite apart from those cases in which juries intentionally
flout the law, juries may fail to apply the law because they are frequently incapable of
understanding legal instructions.89
The view that juries are incapable of properly applying the law is but one of a set
of doubts about jury competence. Many are also skeptical about juries competence to
fulfill their core function of determining the facts. Hence, the final concern
underlying jury mistrust is the idea that juries may be incompetent evaluators of
evidence who cannot be trusted to find facts accurately.90 The classic anxiety is that
juries, as lay people, are vulnerable to misunderstanding the value of certain forms of
proof.91 To summarize, it is feared that juries may be unable or unwilling to judge
cases impartially, to apply the law faithfully, and to find facts accurately.
2. Jury-Control Strategies
Thus, trial by jury is viewed both as a cherished feature of the legal system and as
a potential source of wrong decisions. The common law has maintained this
ambivalent posture over centuries by preserving jury trial while devising procedural
norms to manage the perceived risks to accuracy. Throughout the history of the jury,
124 E.R. 1006 (C.P.)). Bushell sat on the jury that acquitted prominent Quakers William Penn and
William Mead of unlawful assembly, notwithstanding the fact that Penn and Mead had been preaching
in the street. The case that bears his name established that the jury was the judge of the facts and that
individual jurors could not be punished for reaching a verdict that the judge thought was incorrect.
86 In 1985, an English jury acquitted Clive Ponting of offences under the Official Secrets Act, 1911
(U.K.), 1 & 2 Geo. V, c. 28, s. 2, as rep. by Official Secrets Act 1989 (U.K.), 1989, c. 6, s. 16(4), Sch.
2, when he disclosed classified documents revealing that government ministers had lied to Parliament
about events that took place in the Falklands War (Lloyd-Bostock & Thomas, supra note 48 at 10).
87 Abolitionist American juries nullified the law in cases prosecuted under the Fugitive Slave Act, c.
60, 9 Stat. 462 (1850) (Butler, supra note 71 at 703).
88 In some cases, the moral appropriateness of jury nullification can be quite difficult to evaluate.
Debate over what justifies jury nullification has raged in the United States since 1995, when legal
academic Paul Butler published an essay advocating that black jurors acquit factually guilty black
defendants in order to subvert the racist American criminal justice system (ibid.). For commentary, see
Long X. Do, Jury Nullification and Race-Conscious Reasonable Doubt: Overlapping Reifications of
Commonsense Justice and the Potential Voir Dire Mistake (2000) 47 UCLA L. Rev. 1843.
89 See e.g. Jonakait, supra note 60 at 198-217; Valerie P. Hans & Andrea J. Appel, The Jury on
Trial in Walter F. Abbott & John Batt, eds., A Handbook of Jury Research (Philadelphia: American
Law InstituteAmerican Bar Association Committee on Continuing Professional Education, 1999) 3-1
at 3-11. See generally Joel D. Lieberman & Bruce D. Sales, What Social Science Teaches Us About
the Jury Instruction Process (1997) 3 Psychol. Pub. Poly & L. 589.
90 See e.g. Thayer, supra note 19 at 2.
91 See e.g. Wigmore, 1 Evidence, supra note 29 at 632 ([o]ur system of admissibility is based on
the purpose of saving the jurors from being misled by certain kinds of evidence).
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these procedural devices have allowed judges to exercise some measure of control
over jury adjudication.92 Certain such safeguards are built into the basic structure of
the trial: jurors are bound by oath or affirmation to follow the law and to deliver a
verdict based on the evidence, they are instructed that they must follow the law as
explained to them by the trial judge, and the risks of bias and caprice are lessened by
the requirements of group deliberation and unanimity. These and other trial features
promote impartial jury verdicts in accordance with the law.93 In addition, trial judges
occasionally prevent juries from erroneously convicting defendants by directing a
verdict of acquittal.94 And should jury error still occur, in some cases it can be
corrected through the appeal process.
Each of the principal perceived dangers of jury adjudication bias, lawlessness,
and incompetenceis associated with particular jury-control strategies. Bias is
sought to be controlled largely through jury selection.95 A change of venue can be
ordered if pretrial publicity would prevent an impartial jury from being empanelled in
the judicial district where the crime was committed.96 The jury panel from which the
trial jury is drawn can be challenged if improper procedures have resulted in an
unrepresentative panel, a safeguard that occasionally benefits accused persons from
racial minority groups who fear bias from juries on which those groups are
unrepresented.97 Most importantly, the biases of individual jurors are addressed
directly by the challenge-for-cause process, whereby members of the jury panel can
92 See Langbein, Historical Foundations, supra note 6 at 1194-96.
93 The Supreme Court of Canada has catalogued the trial safeguards aimed at improving jury
performance:
The presumption of innocence, the oath or affirmation, the diffusive effects of
collective deliberation, the requirement of jury unanimity, specific directions from the
trial judge and counsel, a regime of evidentiary and statutory protections, the
adversarial nature of the proceedings and their general solemnity, and numerous other
precautions both subtle and manifest all collaborate to keep the jury on the path to
an impartial verdict … (Find, supra note 63 at para. 107).
See also Williams, supra note 82 at paras. 24-25.
94 Defence applications for directed verdicts rarely succeed. In Canada, the case must go to the jury
as long as the prosecutor adduces some evidence on each essential element of the crime (R. v.
Charemski, [1998] 1 S.C.R. 679 at para. 3, 157 D.L.R. (4th) 603).
95 On jury selection in Canadian criminal trials, see generally Tanovich, Paciocco & Skurka, supra
note 82; Granger, supra note 79.
96 Unless a change of venue is ordered, criminal jury trials in Canada and the United States are held
in the judicial district in which the crime was committed. Pretrial publicity is the most common reason
for changes of venue. See Jonakait, supra note 60 at 108-13. See generally Granger, ibid. at 57-79.
97 In Canada, the jury panel can be challenged if the method for selecting it is tainted by partiality,
fraud, or wilful misconduct (Criminal Code, supra note 49, s. 629). However, such challenges
typically fail where the process of summoning jurors was proper, even if the jury panel is in fact
unrepresentative of the wider population in terms of gender or race. See Granger, ibid. at 148-54;
Tanovich, Paciocco & Skurka, supra note 82 at 59-65.
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be excused from sitting on the trial jury if they are adjudged partial.98 Individual
jurors can be excused on the basis of partiality because they hold racist attitudes,
because they have prejudged the case on the basis of out-of-court information,
because they have a personal interest in the outcome, and for other reasons.99 While
jury-selection rules can be manipulated by parties seeking to obtain a favourable jury,
they are intended to prevent jury decision making from being tainted by bias.
The measures taken to control jury lawlessness are relatively modest. To compel
juries to follow the law, courts rely primarily on the requirements that they swear or
affirm to do so and that trial judges instruct them on the law.100 While jurists hope and
expect that the oath and legal instructions will lead juries to properly apply the law, as
jury control devices they are potentially ineffectual and essentially hortatory in
nature. Another procedural norm aimed at requiring jurors to follow the law is purely
negative: juries in most jurisdictions cannot be told of their power to nullify laws and
must decide to ignore the law on their own.101 The weakness of these devices may
well reflect ambivalence about the jurys ability to ignore or moderate that law, which
is viewed at once as an element of defensive safeguard and a source of lawlessness in
the system.102
Just as the risks of lawlessness and bias are associated with certain jury-control
strategies, the danger that juries may be incompetent fact-finders lies at the root of a
set of procedural norms. Rules of evidence limit or at least influence juries access to
and evaluation of evidence, often for the purpose of improving fact-finding accuracy.
Some of those rules are directed at controlling a perceived problem of jury
incompetence. The extent to which jury incompetence is a realand not imagined
problem, and the extent to which particular evidence doctrines are in fact aimed at
controlling it, will be addressed below. For now, it suffices to observe that rules of
evidence give judges some measure of control over jury fact-finding, a control that is
thought to keep some inherent weaknesses of jury fact-finding in check.
Another procedural device that permits judges to influence juries evaluation of
evidence is the judges power to review the evidence and comment on its value. This
judicial power of comment has been eliminated in most U.S. states by constitutional,
98 Section 638(1)(b) of the Criminal Code permits both the prosecution and the defence to question
individual jurors on the grounds that they are not indifferent between the Queen and the accused
(ibid.). Jurors judged partial during this questioning are dismissed. In addition to this [c]hallenge for
cause process (ibid.), both parties in a Canadian criminal case may challenge a limited number of
jurors peremptorily (that is to say, with no stated reason) (ibid., s. 634).
99 See e.g. Parks, supra note 82 (bias against black accused); Williams, supra note 82 (bias against
aboriginal accused); Sherratt, supra note 44 (pretrial publicity).
100 See Morgentaler, supra note 51 at 76-78; Find, supra note 63 at para. 107.
101 See Morgentaler, ibid. at 78-79 (finding that it is improper to inform the jury that it may ignore
the law because while it has a de facto power to do so, it has no right to do so). In agreement is
Sparf v. United States, 156 U.S. 51 (1895).
102 See Parts II.A.2 and II.B.1.
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statutory, or common law no-comment rules,103 and even in those American
jurisdictions where such commentary would be permissible, it is rarely offered in
practice.104 Other jurisdictions, like England and Canada, retain the practice and
impose a positive duty on trial judges to review the evidence.105 In Canada, the trial
judge must review the evidence and may choose to offer opinions on its weight,
provided that the jury is told that the judges views on the evidence are not binding.106
This power to comment constitutes a potent tool for judicial influence over the jury,
one that some argue improves the reliability of jury adjudication by offering needed
professional assistance in the evaluation of evidence.107 Together with the law of
evidence, judicial comment on the evidence arguably compensates for the
apprehended deficiencies of juries as finders of fact.
3. The Tradition of Jury Control
Arguably then, modern trial procedure incorporates a complex system of jury-
control devices, including jury-selection rules aimed at excluding biased individuals,
evidentiary rules that control the flow of information at trial, binding judicial
instructions on the law, and influential judicial comments on the evidence.108
Historically, common law judges had other ways of controlling juries.109 Although a
full review of this historical tradition is beyond the scope of this analysis, a brief
discussion of the ways in which English judges exercised control over juries until the
eighteenth century will highlight some distinctive features of the modern system.
One infamous historical form of jury control was the punishment of jurors who
delivered false verdicts.110 This practice was ended in 1670 by Bushells Case, which
103 King, supra note 50 at 48. Judicial comment on the evidence remains permissible in the federal
system and in a minority of states (ibid.). See also Kenneth A. Krasity, The Role of the Judge in Jury
Trials: The Elimination of Judicial Evaluation of Fact in American State Courts from 1795 to 1913
(1985) 62 University of Detroit Journal of Urban Law 595.
104 Vidmar, Common Law Jury, supra note 59 at 42.
105 Ibid. at 42.
106 See R. v. Gunning, 2005 SCC 27, [2005] 1 S.C.R. 627 at para. 27, 253 D.L.R. (4th) 76; Michael
Hall, Judicial Comment and the Jurys Role in the Criminal Trial (2007) 11 Can. Crim L. Rev. 247
at 249.
107 See Langbein, Mixed Court, supra note 45 at 202 (arguing that it is a mistake to deny juries
the benefits of such professional assistance). See also John Henry Wigmore, Evidence in Trials at
Common Law, rev. ed. by James H. Chadbourn (Boston: Little, Brown, 1981) vol. 9 at 665-66
[Wigmore, 9 Evidence]. But see Hall, supra note 106 at 266.
108 See e.g. Langbein, Origins, supra note 2 at 321; Langbein, Mixed Court, supra note 45 at 202;
Vidmar, Common Law Jury, supra note 59 at 41-46.
109 See e.g. Thayer, supra note 19 at 137-82.
110 On the punishment of jurors in criminal cases, see Thomas Andrew Green, Verdict According to
Conscience: Perspectives on the English Criminal Trial Jury, 12001800 (Chicago: University of
Chicago Press, 1985) at 140-43. Civil juries could be punished through a process called the attaint, in
which a second, larger jury determined whether the first jury was guilty of perjury for delivering a
219
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2008]
declared juries free to judge the evidence for themselves.111 Until that time, early
modern criminal juries could be fined or imprisoned if they insisted on acquitting
when the judges thought a guilty verdict was warranted.112 Generally, such
punishment was justified on the basis that jurors who delivered false verdicts did so
wilfully, but no proof of wilfulness appears to have been required. Instead, acquittals
might be attributed to juror corruption or dishonesty whenever judges thought the
evidence justified conviction.113 Evidently, the courts that punished defiant jurors
equated incorrect results with jury misconduct.114
With the benefit of hindsight, the flaws of this approach are manifest. No modern
observer will fail to notice that it rests on the dubious assumption that judges
somehow know whether juries verdicts are correct. Moreover, the tendency to
conflate misdecision and wrongdoing obscures the possibility of good-faith error.
While juries might sometimes flout the law intentionally, they also make honest
mistakes. Modern jury-control techniques aimed at managing the risk of adjudicative
incompetenceevidentiary rules and judicial comment on the evidenceappear
primarily directed at controlling the risk of error in this true sense.
It is often assumed that Bushells Case ushered in a new era of jury autonomy.115
However, in the decades after Bushells Case, judges continued to exercise control
over jury decision making in a surprising variety of ways.116 The judges power to
comment on the evidence constituted at that time a wholly unrestricted power to
comment on the merits of the case.117 Although the practice was probably rare, it was
considered proper for judges to tell juries how they should decide the cases before
them.118 And when a jury had the temerity to return a verdict with which the judge did
not agree, [i]t was open to the judge to reject a proffered verdict, probe its basis,
false verdict (Theodore F.T. Plucknett, A Concise History of the Common Law, 5th ed. (London:
Butterworth & Co., 1956) at 131-32).
111 Supra note 83.
112 This punishment was visited upon the jurors who in 1554 acquitted Sir Nicholas Throckmorton
of High Treason contrary to the exhortations of the bench (T.B. Howell, ed., A Complete Collection of
State Trials and Proceedings for High Treason and Other Crimes and Misdemeanors from the Earliest
Period to Year 1783, vol. 1 (London: T.C. Hansard, 1816) at 900-02).
113 Green, supra note 110 at 143.
114 See Thayer, supra note 19 at 137. Early juries were thought to possess independent, original
knowledge of the facts … , and not merely inferential and reasoned knowledge (ibid.). On this view
of jury epistemology, wrong decisions were thought to arise from wilful misconduct (ibid.).
115 John H. Langbein, The Criminal Trial before the Lawyers (1978) 45 U. Chicago L. Rev. 263 at
285 [Langbein, Criminal Trial] (observing that, according to most commentators, Bushells Case
marks the triumph of jury autonomy).
116 See ibid. at 284-300. See also Langbein, Origins, supra note 2 at 321-31; Green, supra note 110
117 Langbein, Criminal Trial, supra note 115 at 285. See also Beattie, supra note 2 at 345.
118 Langbein, ibid. at 285-86. The Supreme Court of Canada recently held in Krieger that a trial
judge may not direct a jury to convict a criminal accused (supra note 71).
at 274.
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argue with the jury, give further instruction, and require redeliberation.119 Although
none rises to the coercive extreme of fining or imprisoning errant jurors, the various
ways in which judges could influence or correct jury verdicts in the decades after
Bushells Case indicate that juries were still not entirely free to come to their own
conclusions.120 Judges retained the power to dominate the jury and the trial as a
whole.121
The domineering tactics of early modern judges throw an important feature of
contemporary practice into relief. Whereas historically it was possible to correct jury
misdecision ex post facto, modern jury-control procedures aim to prevent juries from
returning incorrect verdicts.122 The potential for jury bias to distort verdicts, for
example, is dealt with not by retrospectively detecting those cases in which the risk
has materialized, but rather by anticipating the problem and excluding partial jurors
ex ante. Similarly, in our system, evidence is meticulously filtered and regulated
before it is put before the jury.123 And like evidentiary regulation, judicial instructions
and comments seek to equip juries in advance with the analytical tools needed for
fact-finding.124 The limited reviewability of their verdicts means that even when a
contemporary jury decides a case wrongly, normally the outcome will stand. As a
result, our system of jury control focuses on prevention: Prophylaxis substitutes for
cure.125
The current system of jury control is, then, but a shadow of its former self. A
tradition of judicial domination of the jury has given way to a more refined set of
devices designed to guide and influence jury decision-making. This modern system is
more concerned with good-faith error than with corruption and the wilful falsification
of verdicts, and it is oriented toward preventing, rather than correcting, wrong
decisions.
C. Evidence Law as Jury Control
The foregoing discussion has proceeded on the assumption that evidence law is
the centrepiece of a modern system of jury control. And indeed, this is the orthodox
view. Jury control constitutes the most time-honoured and widely-accepted
119 Langbein, ibid. at 291. Also among the jury-control techniques at the judges disposal was the
power to recommend a pardon, which could defeat a jurys ill-considered decision to convict (ibid. at
296-97).
120 See Langbein, Historical Foundations, supra note 6 at 1195-96. See also Beattie, supra note 2
at 406-410.
121 See Langbein, Criminal Trial, supra note 115 at 295; Beattie, supra note 2 at 408.
122 See Langbein, Origins, supra note 2 at 330; Langbein, Mixed Court, supra note 45 at 202.
123 See Damaka, Evidence Law Adrift, supra note 3 at 12.
124 See Kunert, supra note 23 at 124.
125 Langbein, Historical Foundations, supra note 6 at 1195. See also Damaka, Evidence Law
Adrift, supra note 3 at 12.
L. DUFRAIMONT EVIDENCE LAW AND THE JURY
2008]
explanatory principle126 of evidence law. According to this principle or theory,
evidence law improves fact-finding accuracy by preventing inexperienced, untrained,
emotionally
jurors from reasoning
inappropriately from certain problematic forms of proof. On this view, juries are
prone to be led astray by unreliable and prejudicial evidence. The danger that
evidence might mislead juries is frequently discussed by courts, and has been offered
as an explicit justification for various evidence rules.127
labile, and potentially
incompetent
221
lay
1. The Orthodoxy
Many scholars have embraced the jury-control theory of evidence law. James
Bradley Thayer pronounced evidence law the child of the jury,128 a declaration of
paternity that has loomed large in evidence scholarship for more than a century. In his
view, evidence law was primarily directed at compensating for the jurys apprehended
incompetence in evaluating evidence and finding facts.129 Since Thayer, many
scholars have argued or simply assumed that jury control is the central purpose or
principle underlying evidence law.130 Wigmore, for example, emphasized the role of
the jury in the origin and maintenance of evidence law.131
Probably the most influential modern proponent of the jury-control theory of
evidence law is John Langbein, who buttresses with historical evidence his claim that
evidence law is directed at controlling the jury. He demonstrates that between the
mid-eighteenth and late-nineteenth centuries, the judges power to control and correct
jury verdicts was drastically curtailed.132 As discussed above, at the beginning of this
period, judges could dominate jury decision making by exercising a sweeping
authority to comment on the evidence, and even by such heavy-handed tactics as
rejecting verdicts and requiring redeliberation.133 By the end of this century of
126 The term explanatory principle is used by Nance to describe a vehicle for understanding
existing rules of evidence (Nance, Best Evidence, supra note 8 at 270). The same kind of principle
has been labelled an organizing principle by Imwinkelried (supra note 8 at 1096).
127 See e.g. Corbett, supra note 26 ([t]here is perhaps a risk that if told of the fact that the accused
has a criminal record, the jury will make more than it should of that fact at 690-91); Berkeley, In re
(1837), 4 Camp. 401, 171 E.R. 128 [Berkeley cited to E.R.] ([i]n England, where the jury are the sole
judges of the fact, hearsay evidence is properly excluded, because no man can tell what effect it might
have upon their minds at 135 ×.).
128 Thayer, supra note 19 at 47.
129 Ibid. at 2.
130 On the persistence of Thayers idea, see Damaka, Evidence Law Adrift, supra note 3 at 2;
Nance, Best Evidence, supra note 8 at 279. Among those who assume without argument the
correctness of this view are King, supra note 49 at 48-49; David M. Paciocco, Evidence About Guilt:
Balancing the Rights of the Individual and Society in Matters of Truth and Proof (2001) 80 Can. Bar
Rev. 433 at 449.
131 Wigmore, 1 Evidence, supra note 29 at 632.
132 Origins, supra note 2 at 330; Historical Foundations, supra note 6 at 1195-96.
133 See supra notes 116-120 and accompanying text.
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transition, these broad judicial powers had been severely restricted or eliminated
altogether.134 Over roughly the same period, the lawyer-dominated system of
adversary trial took hold and the modern law of evidence was established.135
Langbein draws a connection among these three historical developments: the
weakening of the judges power over the jury, the growing role of adversary lawyers,
and the emergence of evidence law. The decline of judicial dominance over jury
decision-making was gradual and began before the advent of adversarial trial, but the
development of adversarialism contributed to the weakening of the old system of
judicial superintendence of jury verdicts and to the development of the new system of
preventive jury control.136 The older mechanisms were increasingly unsustainable as
the judges dominance waned and the trial came to be dominated by lawyers.137 As the
former system declined, new jury-control devices grew to fill the void. Hence, the
modern law of evidence developed at the centre of a new system of jury control that
was consistent with the adversarial nature of the modern trial.
Some scholars have argued that Langbeins earlier work undermines the jury-
control theory by linking the development of modern evidentiary regulation with the
advent of mature adversary trial.138 Such a suggestion misinterprets Langbeins
scholarship. While Langbein certainly identifies the development of adversary
procedure as a precipitating event that encouraged the establishment of evidence law,
he also unequivocally endorses the explanatory principle of jury control. Indeed, it is
unfortunate that Langbein has been misinterpreted in this way, as he has consistently
claimed that jury control is the basic purpose of evidence law.139 From the Middle
Ages to our own day, he declared in 1996, the driving concern animating the
Anglo-American law of evidence has been to protect against the shortcomings of trial
by jury.140
However numerous and influential have been its advocates, the jury-control
theory of evidence law has also often been doubted. Critics have questioned its
explanatory power, suggesting that jury control represents neither the historical origin
nor the most persuasive analytical justification for some important evidence
doctrines. Moreover, the claim that juries are poor fact-finders has been criticized as
134 Langbein, Origins, supra note 2 at 330; Langbein, Historical Foundations, supra note 6 at
135 Langbein, Historical Foundations, ibid. at 1201.
136 Origins, supra note 2 at 331.
137 Historical Foundations, supra note 6 at 1201.
138 Nance refers to Langbeins recent historical scholarship arguing that the modern rules of
evidence were instituted primarily for the control of lawyers rather than for the control of juries
(Best Evidence, supra note 8 at 229 ×.). See also Imwinkelried, supra note 8 at
1073 (arguing that Langbeins historical research debunks the jury-control theory of evidence law).
139 The very article cited by Nance and Imwinkelried to support their claims that Langbeins
research undermines the jury-control principle describes the law of evidence as the most prominent
modern instrument of jury control (Criminal Trial, supra note 115 at 300).
140 Historical Foundations, supra note 6 at 1194.
1196.
L. DUFRAIMONT EVIDENCE LAW AND THE JURY
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empirically groundless. The explanatory power of the jury-control principle and the
difficult problem of jury competence will be addressed in turn.
223
2. Explanatory Power
The explanatory principles of evidence law purport to justify evidence rules
analytically, to describe their historical origins, or both.141 The jury-control principle
has been criticized on the basis that its explanatory power is weak in both respects.
Most frequently, these arguments have focused on the exclusion of hearsay. The idea
that the hearsay rule was developed to prevent untrained and inexperienced lay juries
from overvaluing unreliable second-hand information was popular among nineteenth-
century judges,142 and has regularly been advanced by scholars up to the present
day.143
But, as several scholars have noted, apprehensions of jury incompetence were not
uppermost in the minds of the seventeenth- and eighteenth-century judges whose
concerns about hearsay hardened into an exclusionary rule.144 Instead, the historical
origins of the hearsay rule lie in concerns about lack of oath and cross-examination,
process values that are crucial to the proper functioning of the adversary system. By
the closing years of the eighteenth century, when the hearsay rule had taken hold in
the civil and criminal courts,145 concerns about the oath and cross-examination
requirements had both been established as rationales for the exclusion of out-of-court
statements.146 Lack of oath appears to have been the principal concern in the earlier
cases, while lack of cross-examination came to be recognized as the dominant
rationale for the hearsay rule by the beginning of the nineteenth century.147
141 On the distinction between the historical approach of identifying the origins of evidentiary rules
and the analytical approach of examining their possible justifications, see Damaka, Evidence Law
Adrift, supra note 3 at 3.
142 See e.g. Wright v. Doe d. Tatham (1837), 7 Ad. & E. 313, 112 E.R. 488 at 512 (Exch. Ct.);
Berkeley, supra note 124 at 135. See also Williams, supra note 35 at 205.
143 See e.g. Frank, supra note 36 at 123; Langbein, Historical Foundations, supra note 6 at 1195.
144 See Edmund M. Morgan, The Jury and the Exclusionary Rules of Evidence (1937) 4 U.
Chicago L. Rev. 247 at 252-53 [Morgan, Exclusionary Rules]; Morgan, Problems of Proof, supra
note 10 at 106-07; Williams, ibid. at 206; Richard D. Friedman, No Link: the Jury and the Origins of
the Confrontation Right and the Hearsay Rule in John W. Cairns & Grant McLeod, eds., The
Dearest Birth Right of the People of England: The Jury in the History of the Common Law (Oxford:
Hart, 2002) 93 at 98.
145 See Langbein, Origins, supra note 2 at 242.
146 See e.g. Morgan, Exclusionary Rules, supra note 144 at 253; Williams, supra note 35 at 206.
147 See Langbein, Origins, supra note 2 at 237, 245-47. This shift in emphasis probably occurred
because, since the 18th century, the oath requirement has increasingly been seen as an empty
formality, ineffectual as a guarantee of truthful testimony. See ibid. at 246; Stephan Landsman, The
Rise of the Contentious Spirit: Adversary Procedure in Eighteenth Century England (1990) 75
Cornell L. Rev. 497 at 598; Sir James Fitzjames Stephen, A History of the Criminal Law of England,
vol. 1 (London: MacMillan, 1883) at 401. By contrast, faith in the power of cross-examination to
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This adversary-system explanation remains the most analytically successful
justification for the hearsay rule. Second-hand evidence cannot be subjected to the
rigours of adversarial testing. By requiring witnesses to swear oaths, submit to cross-
examination, and testify live in court, the adversary process provides triers of fact
with the information they need to assess witnesses sincerity, narration, perception,
and memory.148 Triers of fact are in no position to judge the trustworthiness of
unsworn, uncross-examined statements made outside their presence. The Supreme
Court of Canada has repeatedly affirmed that the hearsay rule is grounded in unease
about the lack of opportunity to test the reliability of out-of-court statements.149 The
historical and analytical salience of this adversary-system explanation seriously
undermines the idea that the hearsay rule can be explained as a jury-control device.
The jury-control explanation for the hearsay rule also conflicts with the available
empirical information about jury behaviour. Far from overvaluing second-hand
information, as the jury-control theory suggests juries do, there is some preliminary
evidence suggesting that juries place little weight on hearsay evidence.150 Just as an
apprehension of jury incompetence does not explain the historical origins of hearsay
law, jury control fails to provide a plausible justification for the rule.
Advocates of the jury-control principle do not, however, put their best foot
forward when they offer the hearsay rule as an example of a jury-control device.
Other evidence doctrines are more plausibly explained by reference to jury mistrust.
Rules respecting prejudicial evidence of bad character, prior bad acts, and criminal
history are examples.151 To reason properly from the accuseds criminal record, for
example, arguably requires a working understanding of the justice system and its
norms, something lay juries might reasonably be expected to lack.152 The exclusion of
such evidence may therefore be explained as a way of keeping in check the jurys
reveal true facts has remained strong over time. See e.g. R. v. Lyttle, 2004 SCC 5, 1 S.C.R. 193 at para.
1, 235 D.L.R. (4th) 244.
148 Edmund M. Morgan, Hearsay Dangers and the Application of the Hearsay Concept (1948) 62
Harv. L. Rev. 177. See also Andrew L.-T. Choo, Hearsay and Confrontation in Criminal Trials
(Oxford: Clarendon Press, 1996) at 11-12, 16-33; Landsman, supra note 147 at 565.
149 See Khelawon, supra note 32 at para. 58; R. v. Starr, 2000 SCC 40, [2000] 2 S.C.R. 144 at paras.
159-60, 190 D.L.R. (4th) 591 [Starr]; R. v. B. (K.G.), [1993] 1 S.C.R. 740 at 763-64, 61 O.A.C. 1.
150 One Canadian mock-jury study on this point is Angela Paglia & Regina A. Schuller, Jurors Use
of Hearsay Evidence: The Effects of Type and Timing of Instructions (1998) 22 Law & Human
Behaviour 501. In agreement is Peter Miene, Roger C. Park & Eugene Borgida, Juror Decision
Making and the Evaluation of Hearsay Evidence (1992) 76 Minn. L. Rev. 683; Richard F. Rakos &
Stephan Landsman, Researching the Hearsay Rule: Emerging Findings, General Issues, and Future
Directions (1992) 76 Minn. L. Rev. 655.
151 Morgan was generally hostile to jury-control explanations for evidence rules, but he
acknowledged that rules excluding prejudicial evidence or evidence that might confuse the issues owe
their existence and persistence largely, though not entirely, to the jury (Exclusionary Rules, supra
note 144 at 257). But see Damaka, Evidence Law Adrift, supra note 3 at 31-32.
152 See Nance, Best Evidence, supra note 8 at 288.
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2008]
inclination to reason improperly from this evidence.153 The empirical evidence is
difficult to interpret; it suggests but does not clearly establish that jurors are
improperly influenced by negative information about the accuseds antecedents.154
However, the jury-control principle arguably justifies rules restricting such evidence
because there exists a plausible risk that juries might rush to condemn defendants
who have unsavoury histories irrespective of the evidence particular to the charge.155
An even stronger example of the explanatory power of the jury-control rationale
is the rule excluding involuntary confessions.156 The confessions rule reflects in part a
concern that coerced confessions are potentially unreliable but deceptively persuasive
in the eyes of the jury. This concern is borne out by the social-science literature,
which demonstrates, first, that people generally believe that innocent suspects do not
confess except under torture, and second, that false confessions are not uncommon
153 Of course, such evidence is not always excluded. In Canada, when an accused puts his or her
character in issue, criminal record evidence is admissible under s. 666 of the Criminal Code to
neutralize the accuseds claim of good character (supra note 49). Where the accused does not put
character in issue but chooses to testify, the record is admissible on the issue of the accuseds
testimonial credibility but not on the issue of propensity to commit the offence, and can be excluded
entirely if the prejudicial effect of admitting the record exceeds its probative value. See Corbett, supra
note 26. Where an accused neither testifies nor raises the issue of character, the accuseds criminal
record is inadmissible.
154 Two 30-year-old Canadian studies based on participants reactions to short written case
descriptions suggest that evidence of prior convictions strongly influences jurors assessments of guilt
(A.N. Doob & H.M. Kirshenbaum, Some Empirical Evidence on the Effect of s. 12 of the Canada
Evidence Act Upon an Accused (1972) 15 Crim. L.Q. 88; Valerie P. Hans & Anthony N. Doob,
Section 12 of the Canada Evidence Act and the Deliberations of Simulated Juries (1976) 18 Crim.
L.Q. 235). In agreement are Roselle L. Wissler & Michael J. Saks (On the Inefficacy of Limiting
Instructions: When Jurors Use Prior Conviction Evidence to Decide on Guilt (1985) 9 Law &
Human Behaviour 37). But see V. Gordon Rose, Social Cognition and Section 12 of the Canada
Evidence Act: Can Jurors Properly Use Criminal Record Evidence? (Ph.D. Thesis, Simon Fraser
University, 2003) [unpublished, archived at UMI ProQuest Digital Dissertations] (reporting a
Canadian simulation study in which criminal history evidence did not affect individual verdicts). A
British simulation study indicates that a recent, similar criminal conviction increases jurors
perceptions of guilt, but also, surprisingly, suggests that a previous dissimilar criminal conviction
might lower jurors likelihood of finding guilt (Sally Lloyd-Bostock, The Effects on Juries of
Hearing About the Defendants Previous Criminal Record: A Simulation Study (2000) Crim. L. Rev.
734 at 741-48).
155 Such rules are explicitly grounded on this perceived risk:
The principal reason for the exclusionary rule relating to propensity is that there is a
natural human tendency to judge a persons action on the basis of character. Particularly
with juries there would be a strong inclination to conclude that a thief has stolen, a
violent man has assaulted and a pedophile has engaged in pedophilic acts. Yet the
policy of the law is wholly against this process of reasoning (B.(C.R.), supra note 42 at
744).
In agreement are Corbett, supra note 26 at 690-91; R. v. Handy, 2002 SCC 56, [2002] 2 S.C.R. 908
at para. 31, 213 D.L.R. (4th) 385 [Handy].
156 See R. v. Oickle, 2000 SCC 38, [2000] 2 S.C.R. 3, 187 N.S.R. (2d) 201 [Oickle].
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even in the absence of torture.157 Coupled with the recognition that false confessions
represent one of the leading causes of wrongful convictions,158 the disconnect
between popular beliefs and empirical data about the value of confession evidence
offers a convincing justification for the exclusion of coerced confessions. The
Supreme Court of Canada has recently justified the confessions rule in just this
way.159 Here, the jury-control rationale succeeds analytically. Since ordinary people
lack the knowledge to properly evaluate involuntary confessions, such evidence
should be kept from juries.
Similarly, the rule requiring trial judges to caution juries about the frailties of
eyewitness identification evidence can be justified on jury-control grounds. When the
prosecution relies on contested eyewitness identification testimony, Canadian case
law requires that the trial judge caution the jury on the frailties of eyewitness
identification.160 The judge should both warn the jury to be cautious in relying on
such evidence and identify any special weaknesses of the eyewitness testimony in the
case.161 Such judicial warnings are thought necessary because of the danger, widely
recognized by courts and psychologists, that ordinary people may overestimate the
value of unreliable eyewitness evidence and fail to grasp the psychological factors
157 See e.g. Richard A. Leo & Richard J. Ofshe, The Consequences of False Confessions:
Deprivations of Liberty and Miscarriages of Justice in the Age of Psychological Interrogation (1998)
88 J. Crim. L. & Criminology 429 at 430, 444.
158 See Jim Dwyer, Peter Neufeld & Barry Scheck, Actual Innocence: When Justice Goes Wrong
and How to Make it Right (New York: New American Library, 2003) at 365 (calculating that false
confessions contributed to wrongful convictions in 27 per cent of the original trials relating to the first
130 DNA-exoneration cases in the United States); Canada, FPT Heads of Prosecutions Committee,
Report on the Prevention of Miscarriages of Justice (2004) at 3, online: Department of Justice Canada
[Prevention
Report] (identifying false confessions as a major contributor to wrongful convictions in Canada).
159 A majority of the Court held in Oickle that a restatement of the confessions rule was necessary in
order to respond to the problem of false confessions (supra note 156 at para. 32). The majority then
underscored the danger that juries might fail to recognize false confessions, the very occurrence of
which seems counterintuitive. The Court explained:
The history of police interrogations is not without its unsavoury chapters. Physical
abuse, if not routine, was certainly not unknown. Today such practices are much less
common. In this context, it may seem counterintuitive that people would confess to a
crime that they did not commit. And indeed, research with mock juries indicates that
people find it difficult to believe that someone would confess falsely. … However, this
intuition is not always correct. A large body of literature has developed documenting
hundreds of cases where confessions have been proven false … (ibid. at paras. 34-35
[citations omitted]).
160 See e.g. R. v. Hibbert, 2002 SCC 39, [2002] 2 S.C.R. 445 at para. 79, 211 D.L.R. (4th) 223,
Bastarache J., dissenting [Hibbert]; R. v. Carey (1996), 113 C.C.C. (3d) 74 at 79-80, 33 W.C.B. (2d)
74 (Qc. C.A.); Haughton, supra note 26.
161 See e.g. R. v. Canning, [1986] 1 S.C.R. 991, 74 N.S.R. (2d) 90; Hibbert, ibid. at para. 81,
Bastarache J., dissenting.
227
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pointing to unreliability.162 Ultimately, the warnings aim to prevent the wrongful
convictions that are known to result from uncritical acceptance of this evidence.163
Since their purpose is to influence jury fact-finding, the warnings are clearly directed
at jury control. And they can be justified as such, because experience has revealed
that jurors are prone to misjudge the value of this evidence.
Ultimately, the explanatory power of the jury-control principle varies depending
on which evidence doctrine is considered. The hearsay rule cannot be plausibly
explained as jury control, but certain other evidence rules can. Because so much
depends on context, it would be difficult to justify any general conclusion about
whether jury control explains the law of evidence.
3. The Competence Problem
Because it rests on doubts about jury competence, the jury-control principle
cannot be evaluated without grappling with those doubts. Jury-control proponents
argue that evidence rules are justified because they counteract frailties in jury
reasoning, while critics insist that juries high level of adjudicative competence
undermines the jury-control theory.164 This subsection will address what kinds of
competence deficits are imagined to afflict the jury, and proceeds to probe their
empirical groundings. It is argued that, for the purposes of evaluating jury-control
rationales in evidence law, the jurys competence to evaluate evidence should be
assessed in absolute terms rather than in comparison to judicial competence, and in
reference to specific forms of evidence rather than at large. Juries are probably
generally competent to adjudicate, but evidentiary regulation can be justified on jury-
control grounds if juries are prone to making particular kinds of mistakes.
a. Finding a Reference Point
Until recent decades, analysis of jury competence was not particularly careful or
sophisticated. That common people were too inexperienced, emotional, inattentive,
and dim-witted to adjudicate disputes in courts of law appears to have been obvious
162 See e.g. Brian L. Cutler & Steven D. Penrod, Mistaken Identification: The Eyewitness,
Psychology, and the Law (Cambridge: Cambridge University Press, 1995) at 171-209 (reviewing
studies demonstrating that lay people lack knowledge of certain important findings in eyewitness
psychology and are insensitive to the factors correlated with identification accuracy); Elizabeth F.
Loftus & James M. Doyle, Eyewitness Testimony: Civil and Criminal, 3d ed. (Charlottesville, Va.:
Lexis, 1997) at 6-8 (cataloguing various widespread misconceptions among jurors about eyewitness
memory).
163 See e.g. Dwyer, Neufeld & Scheck, supra note 158 at 365 (calculating that mistaken
identification contributed to wrongful convictions in 78 per cent of the original trials leading to the
first 130 DNA-exoneration cases in the United States); Prevention Report, supra note 158 at 3
(identifying eyewitness error as a major contributor to wrongful convictions in Canada).
164 See Part II.C.3.b.
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to some of the common laws most distinguished jurists. For example, Glanville
Williams described the jury as follows:
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They are very often good, kindly souls, skilled at their own jobs, competent and
reliable in the affairs to which they are accustomed; but persons whose ordinary
occupations are of a humble character rarely qualify to be regarded as first-rate
intellectual machines.165
No modern commentator would own up to such brazen elitism, but it is worth noting
that, however framed, evidence rules based on jury-control rationales are somewhat
paternalistic.166 There is always an implicit comparison between jury performance and
some standard of fact-finding excellence of which the jury is deemed to fall short.
One longstanding question is whether jury competence should be measured
against the performance of judges or by some absolute standard.167 Most often, jury
performance is evaluated against that of a single professional judge, a comparison
that appears sensible because it contrasts the two basic trial-court arrangements
available in modern common law procedure. Some view the judgejury comparison
as a necessary underpinning of jury-control rationales in evidence law. On this view,
an evidentiary rule can only be justified on jury-control grounds where a single judge
would deal with the evidence more competently than would a lay jury.168
Consequently, it is argued, evidence of a kind that both professional judges and lay
juries have trouble evaluating cannot be regulated on the basis of any deficiency in
jury fact-finding.169
While ostensibly appealing, this argument cannot ultimately succeed. Frequently,
evidence rules may indeed be justified on jury-control grounds even if a single judge
would fare no better than a jury at analyzing the evidence. The real question is
whether a particular evidentiary doctrine can counteract some weakness in jury
reasoning and improve the accuracy of jury verdicts. In general, that question can be
165 Williams, supra note 35 at 272. See also Frank, supra note 36 at 138-39 (suggesting that jury
trial is an irrational mode of proof, comparable to the ordeals); Thayer, supra note 19 at 2 (describing
the jury as an institution that need[s] … watching, like an errant child).
166 See Ronald J. Allen & Brian Leiter, Naturalized Epistemology and the Law of Evidence
(2001) 87 Va. L. Rev. 1491 at 1502 (suggesting that epistemic paternalism is a feature of evidence
rules in general), citing Brian Leiter, The Epistemology of Admissibility: Why Even Good
Philosophy of Science Would Not Make for Good Philosophy of Evidence (1997) B.Y.U.L. Rev. 803
at 814-15; Dale A. Nance, Naturalized Epistemology and the Critique of Evidence Theory (2001)
87 Va. L. Rev. 1551 at 1556-57 [Nance, Epistemology] (observing that this paternalism exists only
to the extent that evidentiary rules aim at jury control).
167 Neil J. Vidmar, Foreword: Empirical Research and the Issue of Jury Competence (1989) 52:4
Law & Contemp. Probs. 1 at 1, 2 [Vidmar, Jury Competence].
168 See Damaka, Evidence Law Adrift, supra note 3 at 30. See also Nance, Best Evidence, supra
note 8 at 286-87.
169 See Damaka, Evidence Law Adrift, ibid. at 31-32 (dismissing the jury-control rationale for bad
character evidence rules on the basis that the tendency to reason through propensity probably afflicts
judges as well as juries).
229
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answered without reference to any judgejury comparison. If lay juries lack the
cognitive tools to properly evaluate evidence, and if an evidentiary rule can
effectively overcome that weakness, then that rule is justified, irrespective of how a
single judge would perform.
In some contexts, no doubt, comparisons of judge and jury competence represent
an indispensable analytical tool. For example, one who would point to the alleged
incompetence of the jury to advocate the elimination of the jury system and the use of
bench trials in all cases bears the onus of demonstrating that a single professional
judge is better at evaluating evidence than a jury. The judgejury comparison is
therefore relevant to the overall justification of the jury system. Similarly, rules of
evidence operating to replace jury judgment with judicial discretion rely on an
unfavourable comparative evaluation of juries and judges. Rules granting trial judges
discretion to exclude information from the jury are the best examples. Unless a
professional judges evaluation of evidence is considered somehow more trustworthy
than the jurys evaluation, it seems difficult to justify trial judges obligation to
exclude irrelevant evidence,170 much less their discretion to exclude relevant evidence
if its prejudicial effect outweighs its probative value.171 Thus, the judgejury
comparison remains significant where either the wisdom of the jury system itself or
the displacement of jury evaluation by judicial discretion is at stake.
On the whole, however, evidentiary regulation grounded on deficits in jury
competence implies no performance comparison between judge and jury. Most
intrinsic rules transcend individual judicial discretion: they are binding, general rules
that have developed through the work of legislators and appellate courts. In Canada,
almost all of the recent important developments in evidence law have emanated from
the Supreme Court of Canada.172 Like juries, trial judges are subject to these rules:
[I]n administering these sorts of rules the trial judge himself is bound by the
assessments of someone else as to the value of this sort of evidence; thus in this
situation the question may not be whether the trial judges assessment of the
value of evidence is to displace the jurys assessment but is whether some sort
of communally established assessment should displace the jurys right to hear
and evaluate the evidence in question.173
170 See John Henry Wigmore, Evidence in Trials at Common Law, rev. ed. by Peter Tillers (Boston:
Little, Brown, 1983) vol. 1A at 1021 [Wigmore, 1A Evidence]. But see Nance, Best Evidence,
supra note 8 at 272-74.
171 The common law discretion to exclude prejudicial evidence (reaffirmed in Canada in R. v.
Seaboyer, [1991] 2 S.C.R. 577, 83 D.L.R. (4th) 193) assumes that the judge has some reliable
calculus or method for determining the correct value of relevant evidence (Wigmore, 1 Evidence,
supra note 29 at 688).
172 See e.g. Khelawon, supra note 32 (hearsay); R. v. Mohan, [1994] 2 S.C.R. 9, 114 D.L.R. (4th)
419 (expert evidence); Oickle, supra note 156 (confessions); Handy, supra note 156 (accuseds prior
bad acts).
173 Wigmore, 1A Evidence, supra note 170 at 1023. See also Schauer, supra note 7 at 184, 186.
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To the extent that intrinsic rules are justified by the frailties of jury fact-finding, it
need only be shown that such frailties exist and that the communally established rules
of evidence compensate for them in a way that reliably improves jury fact-finding.
In other words, the question is not whether a single judge would do a better job in
evaluating the evidence than a jury, but whether the law has accurately identified
some frailty in jury reasoning and implemented a rule that effectively counteracts it.
Of course it is possibleperhaps even probablethat judges engage in some of the
same kinds of faulty reasoning as juries. Arguably, however, instead of undermining
the jury-control rationale for evidence rules, frailties in judges reasoning actually
strengthen this justification. Because they bind both judges and juries, general
evidentiary norms directed at counteracting known frailties in jury reasoning may
operate to correct those defects when they arise in the reasoning of judges.174
Consider the confessions rule, which I have argued can be justified in part by the
that ordinary people
jury-control principle. Faced with empirical evidence
overestimate the reliability of confession evidence, the Supreme Court of Canada
reaffirmed the exclusion of involuntary confessions partly on the basis that the rule
excludes from the consideration of the jury those confessions most likely to be
false.175 Since it probably does prevent some juries from being led astray by
unreliable confession evidence, the rule can plausibly be justified as a jury-control
device. This justification does not depend on any assumption about how a
hypothetical professional judge might interpret dubious confession evidence. Even if
individual trial judges have as much trouble as juries with this evidence, the
confessions rule can be justified as jury control because it increases the accuracy of
jury decision making.
As a practical matter, it would be difficult to assess the comparative competence
of judges and juries, even if it were desirable to do so. In reality, judicial competence
in evaluating problematic forms of proof like confessions or eyewitness testimony
probably varies widely and lies on average somewhere between jury competence and
the standard of excellence in fact-finding envisioned by appellate courts. But little
empirical evidence is available to shed light on the mental processes of trial judges.176
Juries, on the other hand, have been extensively studied in the psychological
literature. Since jury reasoning is a subject we know something about, it should come
as no surprise that certain rules of evidence are directed at controlling the frailties of
jury fact-finding. The necessarily speculative but plausible conclusion that judges
also have difficulty evaluating problematic forms of proof does not undermine those
174 See Schauer, ibid.
175 See Oickle, supra note 156 at paras. 32-36.
176 See Jennifer L. Devenport, Steven D. Penrod & Brian L. Cutler, Eyewitness Identification
Evidence: Evaluating Commonsense Evaluations (1997) 3 Psychol. Pub. Poly & L. 338 at 356-57
(reviewing studies of attorneys, judges, and jurors knowledge of the factors affecting the accuracy
of eyewitness testimony, and revealing that, while there are many studies of lay knowledge, only a
handful investigate judges beliefs).
L. DUFRAIMONT EVIDENCE LAW AND THE JURY
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jury-control efforts. Evidentiary rules can be justified if they offset the known
weaknesses of jury reasoning, weaknesses that are established not by comparison to
trial judges but by reference to what lawmakers know about the causes of verdict
error and the psychology of proof.
231
b. General and Specific Competencies
The jury-control principle can, then, plausibly justify evidentiary rules that
compensate for some demonstrable deficit in jury fact-finding, but an important
question remains: what are the real deficiencies of juries as finders of fact? The
question of jury competence is not as simple as the legal theorists of former times
imagined. Some still doubt the general competence of juries as finders of fact, but
such radical doubts find little support in the empirical literature. The seminal study on
the matter emerged from the Chicago Jury Project: investigating patterns of judge-
jury disagreement in thousands of actual American criminal trials in the 1950s, the
research produced an overall agreement rate of 75 per cent and found that
disagreement was usually the result of jury leniency.177 Despite its age and some
serious methodological flaws,178 that study is still cited as evidence that juries are no
less competent than judges at deciding cases.179 Since that time, the findings of jury
researchers have suggested that jury fact-finding is remarkably competent.180 The
empirical work consistently indicates that, in general, the strength of the evidence is
the strongest determinant of jury verdicts,181 a finding that supports the conclusion
that, on the whole, juries make competent finders of fact.
This conclusion may appear to defeat the jury-control theory of evidence law. In
reality, however, the fact that juries are generally good fact-finders does not rob the
jury-control principle of all its explanatory power. Jury-control rationales need not be
177 Harry Kalven, Jr. & Hans Zeisel, The American Jury (Boston: Little, Brown, 1966) at 56-59.
178 On the methodological problems with the Chicago Jury Project study, see Michael H. Walsh,
The American Jury: A Reassessment, Book Review of The American Jury by Harry Kalven, Jr. &
Hans Zeisel, (1969) 79 Yale L.J. 142. According to Walsh, Kalven and Zeisels work reveals
little more than that judge and jury decide on[e] in four cases differently. As they
acknowledged, this datum is not particularly useful. We dont know for certain who is
correctjudge or jury. Even if we did, we lack a context in which to decide how much
disagreement is too much. Furthermore, we have not been given a convincing
explanation of why judges and juries disagree (ibid. at 158).
For an argument that the age of the Chicago Jury Project limits its current usefulness, see Vidmar,
Jury Competence, supra note 167 at 4.
179 The continuing relevance of the study is discussed in Vidmar, ibid. at 4; Hans & Appel, supra
note 89 at 3-5.
180 Hastie, Penrod & Pennington, supra note 61 at 230. See also Hans & Appel, ibid. at 3-4 to 3-7.
181 See e.g. Devine et al., supra note 55 ([t]here is ample evidence supporting the conclusion that
SOE [strength of evidence] is the primary determinant of jury verdicts in criminal trials in most
circumstances, but it remains to be determined how important SOE is relative to the many irrelevant
biasing factors that may influence jury verdicts at 686); Jonakait, supra note 60 at 221.
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rooted in any negative judgment of juries overall adjudicative competence, but may,
instead, be based on narrow presuppositions about how juries reason from particular
species of evidence. Courts and commentators make a variety of assumptions about
how juries find factsfor example, that juries are prone to convict defendants with
criminal records irrespective of the weight of the evidence, that they overvalue
potentially unreliable hearsay information or eyewitness testimony, or that they
underestimate the probability of false confessions. Such assumptions may be more or
less correct, but in any event they inform the law of evidence.182
Much depends on the validity of those assumptions, which can only be tested one
at a time. Jury research supports the idea that juries skill in evaluating evidence and
finding facts, while strong in general, varies according to the type of evidence under
consideration. Juries are known to struggle, for instance, in understanding legal
instructions and properly evaluating statistical, scientific, and expert evidence.183
They are apt to place great weight on eyewitness identification and confessions
arising from police interrogations, even in circumstances where the reliability of the
evidence is gravely in doubt.184 Even if we are generally confident in juries fact-
finding abilities, rules regulating these forms of proof may be justified on jury-control
grounds. The issue is the jurys ability to deal with particular forms of evidence rather
than its general ability to find facts: it is a question of specific jury competencies, not
general jury competence.
Understood in this way, the jury-control principle is consistent with the continued
existence of the jury as an important common law institution. With some justification,
courts have been wary of openly embracing the logic of jury control, for fear of
casting aspersions on the jury system itself.185 In the words of Chief Justice Dickson:
It is of course, entirely possible to construct an argument disputing the theory of
trial by jury. Juries are capable of egregious mistakes and they may at times
seem to be ill-adapted to the exigencies of an increasingly complicated and
refined criminal law. But until the paradigm is altered by Parliament, the Court
should not be heard to call into question the capacity of juries to do the job
assigned to them.186
To be sure, when they are based on negative global judgments about jury
competence, jury-control rationales undermine jury legitimacy. Indeed, taken to an
182 See Nance, Epistemology, supra note 166 ([e]mpirical studies conducted in recent decades
have shown that many of the rather condescending assertions lawyers have been making regularly for
decades, indeed for centuries, about how jurors react to evidence are false, or at least considerably off-
target at 1561 ×.); Kunert, supra note 23 ([t]he outcome of cases is largely
determined by the notionsbased largely on guesses, fictions, and assumptionsthat judges have of
the lay fact-finders mind at 133).
183 See Hans & Appel, supra note 89 at 37 to 311. See also Hastie, Penrod & Pennington, supra
note 61 at 231.
184 See supra notes 154-60 and accompanying text.
185 See Damaka, Evidence Law Adrift, supra note 3 at 29; Kunert, supra note 23 at 133-38.
186 Corbett, supra note 26 at 693.
L. DUFRAIMONT EVIDENCE LAW AND THE JURY
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extreme, jury-control rationales might suggest that the jury is best replaced by another
adjudicator, such as a judge.187 However, as long as jury-control efforts are directed at
counteracting specific, demonstrable deficiencies in jury reasoning, they can only be
expected to improve verdict accuracy and enhance jury legitimacy.
233
III. Competing Explanations
The jury is not the only feature of common law trial that raises a danger of error
thought to be amenable to control through evidentiary regulation. Analogous stories
have also been recounted about the adversary system and dangers of false testimony,
with overzealous partisan advocates and dishonest fact witnesses taking the place of
incompetent juries as the weak link in the trial process. In this section, the merits of
these competing explanations will be briefly reviewed. Like jury control, each of the
explanatory principles under consideration accounts to some extent for the law of
evidence. Still, none of the proposed explanations emerges as pre-eminent. On the
whole, the law of evidence trades on a complex set of assumptions about which
features of the adjudicative system, and which actors in the trial, present a risk of
error that requires control.
A. The Adversary System
No other explanation of evidence law matches the jury theory in terms of
longevity or general acceptance. Indeed, only one other explanation poses a serious
challenge: that centered on the adversary system. As this theorys most influential
proponent, Edmund Morgan, pointed out in the 1930s, the adversary feature of our
system is quite as distinctive as is its use of a jury, … and it seems reasonable to
expect that the adversary character of common law proceedings, and not just
concerns about jury competence, would shape the rules of evidence.188 Since
Morgans time, scholars have continued to draw connections between evidentiary
regulation and adversary process.189 Historically, there is little doubt that the rules of
evidence arose in part through judges efforts to even up prosecutorial advantage and
187 Bentham put it this way:
If there be one business that belongs to a jury more particularly than another, it is, one
should think, the judging of the probability of evidence: if they are not fit to be trusted
with this, not even with the benefit of the judges assistance and advice, what is it they
are fit to be trusted with? Better trust them with nothing at all, and do without them
altogether (Rationale of Judicial Evidence, Specially applied to English Practice
(London: Hunt and Clarke, 1827) vol. 5 at 17).
See also Wigmore, 1A Evidence, supra note 170 at 1025.
188 Morgan, Exclusionary Rule, supra note 144 at 248.
189 See e.g. Jenny McEwan, Evidence and the Adversarial Process: The Modern Law, 2d ed.
(Oxford: Hart, 1998) at 26-32; Nance, Best Evidence, supra note 8; Damaka, Evidence Law Adrift,
supra note 3.
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achieve an appropriate balance in criminal procedure.190 It is a more difficult question
whether, analytically, the current system of evidence law can be justified by the
adversary character of common law trials.
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1. Features, Justifications, and Criticisms
Much has been written about adversary or contentious procedure, and there is
broad agreement about what constitute its basic features.191 Adversarial trials, whether
civil or criminal, are essentially contests whose ruling principle is fair play between
formally equal adversaries.192 The parties, through their lawyers, have a significant
measure of autonomy and control over the process: they collect and present the
evidence, and they determine which issues are in dispute.193 Whereas nonadversary
judges are actively involved in developing cases, adversary judges remain relatively
passive as the parties produce the evidence.194 Adversary procedure is governed by a
complex network of formal rules, which the judge is responsible for enforcing
impartially against the parties.195
This system has been justified on a number of grounds, most of which relate to
the party-control feature of the process.196 Frequently, proponents claim that adversary
procedure is the surest method of arriving at the truth about factual disputes.197
Permitting the adversaries to investigate the case and produce the evidence results in
the most thorough airing of relevant information, it is argued, because such a process
puts the power of self-interest and competition to the service of truth seeking.198
Moreover, since adversary procedure prevents judges (and juries) from being
involved in developing the case, it is said to protect their impartiality.199 In addition,
control of the case by the parties rather than the judge is argued to offer some
190 See Murphy, supra note 20 at 2; Langbein, Origins, supra note 2 at 177.
191 See e.g. Stephan Landsman, The Adversary System: A Description and Defense (Washington:
American Enterprise Institute for Public Policy Research, 1984); Lon L. Fuller, The Adversary
System in Berman, supra note 59, 35 at 35; Mirjan Damaka, Evidentiary Barriers to Conviction
and Two Models of Criminal Procedure: A Comparative Study (1973) 121 U. Pa. L. Rev. 506 at 563-
64 [Damaka, Evidentiary Barriers]; Golding, supra note 13.
192 Damaka, Evidentiary Barriers, ibid. at 563-64; Golding, ibid. at 98-104.
193 See e.g. Landsman, supra note 191 at 4.
194 See e.g. ibid. at 2-4; Kunert, supra note 23 at 160-63.
195 On procedural rules in adversary systems, see e.g. Landsmann, ibid. at 4-6; Damaka,
Evidentiary Barriers, supra note 191 at 564. On the judges role in rule enforcement, see e.g.
McEwan, supra note 189 at 2; Strier, supra note 80 at 15.
196 See generally Gary Goodpaster, On the Theory of American Adversary Criminal Trial (1987)
78 J. Crim. L. & Criminology 118 at 121-29.
197 Ibid. at 121; Jackson, supra note 37 at 501.
198 See e.g. Fuller, supra note 191 at 36; Robert J. Kutak, The Adversary System and the Practice
of Law in David Luban, ed., The Good Lawyer: Lawyers Roles and Lawyers Ethics (Totowa, N.J.:
Rowman & Allanheld, 1983) 172 at 174.
199 See e.g. Damaka, Evidence Law Adrift, supra note 3 at 95; Fuller, ibid. at 36, 44-45.
235
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protection from the abuse of official power.200 Party control is also said to protect the
important values of individual autonomy and dignity by permitting individuals to
press their claims against others, including the state.201 Finally, the adversary system
is sometimes argued to be uniquely suited to protecting individual rights and to
inculcating a sense of satisfaction and procedural fairness for participants.202
Like its justifications, criticisms of adversary procedures centre on the control of
the evidence by parties and their lawyers. When parties present their cases in the
context of a partisan contest, normally neither the parties themselves nor their lawyers
have any duty to seek the truth.203 Admittedly, criminal prosecutors are an exception
to this rule, as they are ethically bound to seek justice rather than victory.204 Other
advocates, however, are … attitudinally and ethically committed to winning the
contest rather than to some other goal, such as discovery of truth or fairness to the
opposing side.205 Even the adversary judge as the trier of law has no direct
responsibility to ensure that the truth emerges.206 Insofar as truth seeking is not the
primary role of professional courtroom actors, the adversary system relies on an
expectation of inadvertent truth discovery.207 Not surprisingly, adversary procedure
has been criticized for being insufficiently committed to, and insufficiently likely to
result in, the discovery of truth.208
Critics have pointed to two basic problems: the wealth effect and the combat
effect.209 First, adversary procedure is more advantageous to the wealthy because the
results of litigation often depend on the skill level of the lawyers the parties can afford
200 See e.g. McEwan, supra note 189 at 2-3; Jackson, supra note 37 at 484.
201 See e.g. Alan Donagan, Justifying Legal Practice in the Adversary System in Luban, supra
note 198, 123 at 133 ([a] society fails to respect the human dignity of those within its jurisdiction if it
denies them a fair opportunity to raise questions about what is due to them under the law … [A]ny
social-juridical system in which the adversary system is not an element must fail to respect the dignity
of its members); Monroe H. Freedman, Judge Frankels Search for Truth (1975) 123 U. Pa. L. Rev.
1060 at 1065.
202 See e.g. Golding, supra note 13 at 112-16; Strier, supra note 80 at 28-29, 33.
203 Legal advocates normally have no substantive duty like the healers undertaking to promote
health or the shipbuilders to fashion a seaworthy vessel. There is no Duty to Seek Justice or Duty to
Promote the Quest for Truth (Marvin E. Frankel, Partisan Justice (New York: Hill and Wang, 1980)
at 25).
204 See H. Richard Uviller, The Advocate, The Truth, and Judicial Hackles: A Reaction to Judge
Frankels Idea (1975) 123 U. Pa. L. Rev. 1067 at 1070; Michel Proulx & David Layton, Ethics and
Canadian Criminal Law (Toronto: Irwin Law, 2001) at 639 (noting that, in Canada, the Crown
prosecutor has a dual role as an advocate and a minister of justice).
205 Goodpaster, supra note 196 at 120 ×..
206 See Frankel, Partisan Justice, supra note 203 at 43; McEwan, supra note 189 at 3.
207 Marvin E. Frankel, The Search For Truth: An Umpireal View (1975) 123 U. Pa. L. Rev. 1031
at 1035, 1037 [Frankel, Search For Truth]; Goodpaster, supra note 196 at 124.
208 See e.g. Frank, supra note 36 at 80-102; Frankel, supra note 203 at 12; Strier, supra note 80 at
209 Langbein, Origins, supra note 2 at 1-2 [emphasis omitted].
53-57.
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to pay and the exhaustiveness of the factual inquiries they can afford to make.210
Second, the search for truth can become distorted in the course of adversarial combat.
Zealous advocates are often permitted, even ethically bound, to resort to strategies
that hamper the fact-finders effort to arrive at the truth.211 Where the parties control
its production, the evidence may be incomplete because information that is not
helpful to either party will not be presented.212 That is, a witness with relevant
evidence that might aid the search for truth will not be brought forward if the
witnesss evidence does not support the theory of the case advanced by either
adversary. Furthermore, the information presented may be distorted through
adversarial tactics such as witness preparation, suggestive pretrial questioning, and
even cross-examination, which can be used to destroy the credibility of honest
witnesses.213 Partisan control over gathering and presenting evidence distorts fact-
finding, it is feared, by producing a skewed, incomplete, and misleading evidentiary
picture.
2. Evidence Law as Advocate Control
As noted above, scholars have argued that the adversary character of common
law proceedings explains much of the law of evidence.214 In particular, evidence rules
arguably promote the search for truth in two main ways related to the adversary
system. First, the rules sometimes facilitate the testing of evidence within an
adversary framework. Second, the rules often act to curb the truth-distorting excesses
of adversary process. These two functions of evidentiary regulation will be discussed,
briefly, in turn.
a. Facilitating Adversary Testing
As explained above, adversary procedure vests the parties with responsibility for
developing the evidence. The adversaries are permitted to gather and present their
own evidence, and they are also expected to challenge and test the strength of the
evidence presented by the opposing side. The central mechanism for this adversarial
testing is cross-examination. The opportunity to cross-examine opposing witnesses is
considered fundamental to a fair adversarial contest because cross-examination can
expose falsehoods, weaknesses and inconsistencies in testimony.215 Evidence rules
sometimes operate to protect this opportunity for adversarial testing. Most
importantly, it has already been argued that the hearsay rule is best explained as a
210 See e.g. ibid.; Frank, supra note 36 at 95; Strier, supra note 80 at 51-93.
211 See e.g. Frankel, Search for Truth, supra note 207 at 1038.
212 See e.g. Damaka, supra note 3 at 100; Jackson, supra note 37 at 504.
213 See e.g. Frankel, Partisan Justice, supra note 203 at 16; Strier, supra note 80 at 55-57.
214 See supra notes 185-86 and accompanying text.
215 See R. v. Lyttle, 2004 SCC 5, [2004] 1 S.C.R. 193 at paras. 1, 41-43, 234 D.L.R. (4th) 257
[Lyttle].
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guarantor of adversarial scrutiny.216 Hearsay evidence is presumptively inadmissible
because witnesses must normally testify live in court, where they can be subjected to
cross-examination at the time they give their statements.217
237
b. Restraining Adversarial Excess
Alongside their important role in facilitating the adversarial testing of testimony,
evidence rules have a second function associated with the adversary character of
common law trials. As noted above, party control of the evidence gives rise to a
concern that adversary tactics may hamper the search for truth, and the law of
evidence is frequently explained as a set of restraints on this truth-distorting
adversarial excess.218 As a rationale for evidence law, this theory has been called the
advocate control principle, because it stresses the need to control the machinations
of adversary lawyers in the interests of accurately finding facts.219 The most important
modern proponent of this principle is Dale Nance, who maintains that evidence rules
are informed by a best evidence principle requiring adversaries to furnish the fact-
finders with the epistemically best evidence available.220 On this view, evidence law
recognizes that advocates may be operating under incentives to withhold important
evidence or to otherwise distort the fact-finding process.221 The intrinsic rules of
evidence promote the search for truth by controlling those incentives and compelling
the adversaries to present the court with the most reliable information to be had.222
Some important features of evidence law are persuasively justified by this
advocate-control principle.223 For example, parties may wish to use cross-examination
to put unfounded suggestions to opposing witnesses and thereby to introduce
innuendo and speculation harmful to the adversary. However, in Canada, a partys
216 See supra notes 145-47 and accompanying text.
217 See Khelawon, supra note 32 at paras. 2, 35; Williams, supra note 35 at 203 ([t]he only
satisfactory ground for excluding first-hand hearsay … is to compel the party wishing to tender the
evidence to produce the actual declarant in court for cross-examination); Nance, Best Evidence,
supra note 8 at 282-83. But see Friedman, supra note 38 ([i]f hearsay evidence is excluded on the
ground that it will cause the production of better evidence by the proponentlive testimonyit will
often be a failed bluff at 560).
218 See e.g. Stephan Landsman, Who Needs Evidence Rules, Anyway? (1992) 25 Loy. L.A. L.
Rev. 635 at 635; Nance, Best Evidence, ibid. at 291.
219 The label advocate control is borrowed from Nance, Epistemology, supra note 166 at 1556.
For an early statement of this rationale, see Sir James Fitzjames Stephen, Report of the Select
Committee on the Bill to Define and Amend the Indian Law of Evidence (31 March 1871), reproduced
in Murphy, supra note 20, 65 ([a]ctive and zealous advocates, who have no rules of evidence to
restrain their zeal, would have it in their power to prevent the administration of justice to the basest
purposes . . . at 67).
220 Nance, Best Evidence, supra note 8.
221 See ibid. at 239.
222 Ibid.; Damaka, Evidence Law Adrift, supra note 3 at 84-85.
223 See Nance, Best Evidence, supra note 8 at 281.
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ability to exploit the adversary process in this way is limited by an evidentiary rule
requiring that all suggestions put to witnesses in cross-examination have a good faith
basis.224
The advocate-control principle also provides a persuasive supplementary
justification for the hearsay rule. A party might prefer to have certain information
presented to the fact-finder second-hand, as when the hearsay witness appears more
likeable or trustworthy than the original declarant. However, the hearsay rule ensures
that the fact-finder is not at the whim of the adversary in this respect: as discussed
above, the declarant must come to court so that the evidence can be subjected to
adversarial testing.225 Similarly, the traditional common law exclusion of lay opinion
testimony was directed at ensuring that, instead of hearing lay witnesses evaluation
of the facts, fact-finders heard what witnesses observed and remained free to draw
their own conclusions. And while the general rule against lay-opinion testimony has
been relaxed in the United States and Canada, both jurisdictions have retained a
preference for particularized narrations of witnesses observations.226 Both the hearsay
rule and the surviving lay-opinion rules require adversaries to produce evidence in a
form and from a source that serves the fact-finders epistemic needs rather than the
parties strategic interests.227 In this way, the evidence rules override adversary
preferences and make certain that fact-finders have access to the most reliable and
epistemically useful information available.
B. Dishonesty
A final rationale for evidence lawalbeit one that is less widely accepted than
jury- or adversary-system explanationsis the need to detect and prevent lying.
Controlling dishonesty was among the key motivations of the judges who developed
the law of evidence. In the eighteenth century, when the rules of criminal evidence
were principally established, the English judiciary was plagued by scandals involving
the wrongful conviction of innocent defendants on the basis of perjured testimony.228
The prosecutorial practice of the period, which encouraged false witnessing by
rewarding Crown witnesses and professional thief catchers for implicating others,
was largely responsible.229 Judges responded to the ensuing widespread concern about
224 Lyttle, supra note 215.
225 See Nance, Best Evidence, supra note 8 at 282-83.
226 See ibid. at 286 (arguing that the preference for the most elemental observations of the witness
enshrined in U.S. Fed. R. Evid. 701(a) reflects a concern about providing the fact-finder with the best
available information); R. v. Graat, [1982] 2 S.C.R. 819 at 841, 144 D.L.R. (3d) 267 (permitting
witnesses to testify to their opinions that the accused was impaired by alcohol because the testimony
was merely … a compendious statement of facts that are too subtle and too complicated to be narrated
separately and distinctly).
227 See Nance, Best Evidence, supra note 8 at 264, 274, 286.
228 See e.g. Langbein, Origins, supra note 2 at 148-65.
229 Ibid.; Imwinkelried, supra note 8 at 1078-81.
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the potential for perjury partly through rules of evidence. Most notably, the
requirement that accomplice testimony be corroborated was developed during this
period to control the problem of dishonest Crown witnesses.230 The corroboration rule
lives on in Canada in the form of a judicial discretion, and in some cases, a
requirement to warn the jury about accepting the testimony of unsavoury
witnesses.231 It was and is manifestly directed at controlling the problem of lying and
deceit.
The chief proponent of the dishonesty-centred explanation of evidence law is
Edward Imwinkelried, who suggests that various evidentiary doctrines are explained
in part by a concern about lying.232 Even the exclusion of hearsay evidence is partly
grounded on a dishonesty-control rationale, since cross-examination is needed to test
the declarants sincerity, among other aspects of testimonial reliability.233 This idea
that the danger of deceit informs the hearsay rule is borne out in Canadian law, where
the presence or absence of a motive to lie on the part of the declarant frequently arises
as a factor when courts consider whether hearsay evidence is reliable enough to be
admitted.234 As Imwinkelrieds work establishes, the risk of false testimony is an
important idea running through evidence law.
Indeed, concern about deception so pervades evidence law that one might wonder
whether, instead of explaining them, worries about witness dishonesty are just an
inherent part of truth-pursuing evidence rules. By definition, intrinsic rules are
concerned about the risk of error arising from prejudicial and unreliable (that is,
faulty, or factually incorrect) evidence. Testimony can be faulty either because it is
mistaken or dishonest. Perhaps it is not surprising, then, nor particularly illuminating,
to observe that a concern about dishonesty constitutes one of the concerns at the root
of intrinsic rules. Significantly, explanations connected to the jury and the adversary
system can both subsume concerns about the risk of false testimony.235 Arguably,
dishonest testimony becomes most problematic when the inexperienced and
credulous jury does not recognize it for what it is, or when, absent proper adversarial
testing, its defects are not exposed. It would therefore be wrong to suppose that the
jury and adversary system explanations for evidence law cannot account for the laws
anxiety over witness dishonesty. Ultimately, whether or not mendacity control is best
understood as an independent explanatory principle, it is important to be mindful of
the extent to which evidentiary rules are directed at a perceived risk of dishonesty.
230 See Langbein, Origins, supra note 2 at 165; Imwinkelried, ibid. at 1080.
231 Vetrovec, supra note 42 at 820.
232 Imwinkelried, supra note 8 (pointing to this explanation for rules about witness competence, the
oath, the authentication of documents, bad character evidence, hearsay, and opinion evidence).
233 See ibid. at 1089-90. See also supra note 148 and accompanying text.
234 See Khelawon, supra note 32; Starr, supra note 149; R. v. Smith, [1992] 2 S.C.R. 915, 94 D.L.R.
235 But see Imwinkelried, supra note 8 at 1088 (equating the principle that the parties should
produce the best available evidence with a single-minded concern about innocent errors).
(4th) 590.
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C. The Complex Picture
The debate over the explanatory principles of evidence law is largely a debate
about whom to mistrust. Is our fear that juries may misconstrue the evidence, that
adversaries may obscure the truth, or that witnesses may perjure themselves? Of
whom are we afraid, and whom are we trying to control? It seems doubtful that these
questions can ever be answered in any decisive way.
Certainly some authors identify one explanatory principle as the primary,
underlying principle of evidence law. Thayer, among others, focused on the jury,
while recently evidence scholars have suggested that the central rationale for
evidence law lies elsewhere. Nance argues that the best evidence principle, which is
concerned with advocate control, constitutes a superior explanatory principle to the
traditional jury-centred rationale for evidence law. According to Imwinkelried, both
of those explanatory principles are inferior to the dishonesty-control rationale, which
he claims constitutes the best explanatory hypothesis for the logical structure of
Evidence law.236 The modern theorists admit forthrightly that no one principle
explains the totality of evidence law, an admission that militates in favour of
interpreting their claims modestly.237 But beyond arguing the explanatory power of
the various rationales for evidence law, these scholars purport to choose the best,
unifying theories, or even to explain the laws logical structure.238 Such ambitious
claims are difficult to defend.
The search for an organizing principle239 of evidence law is vain because
evidence law is not organized around a principle. Given the ad hoc nature of
evidentiary regulation, there is no reason to believe that the various possible
rationales for evidence rules are mutually exclusive. A more tenable position is to
recognize that various factors, including the trial features under consideration, play a
role in explaining evidence law.240 The origins and justifications of evidentiary rules
are best uncovered in specific doctrinal contexts. And one could easily add yet more
layers of complexity to the picture. Issues that cannot entirely be disentangled from
the explanatory principles include extrinsic policy considerations like fairness and
due process, as well as concerns about the efficient conduct of the trial process, such
as affordability, speed, and finality.
This complexity has long been recognized by evidence scholars, though the
subtlety of the positions taken by historical participants in this debate has often been
overlooked. For example, Wigmore is usually considered a champion of the jury-
control theory of evidence law, but he also explicitly recognized the explanatory role
236 Ibid. at 1072.
237 See ibid. at 1095; Nance, Best Evidence, supra note 8 at 287.
238 Imwinkelried, supra note 8.
239 Ibid. at 1096.
240 See e.g. Murphy, supra note 20 at 2.
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of, among other factors, adversarial excess and witness dishonesty.241 As a body of
doctrine, he insisted that evidence law had a sound basis in the experience of human
nature:242
241
That human nature is represented in the witnesses, the counsel, and the jurors.
All three, in their weaknesses, have been kept in mind by the law of evidence.
The multifold untrustworthinesses of witnesses; the constant partisan zeal, the
lurking chicanery, the needless unpreparedness of counsel; the crude reasoning,
the strong irrational emotions, the testimonial inexperience of jurorsall these
elements have been considered.243
Similarly, Edmund Morgan is frequently remembered for having refuted the jury-
control theory of evidence law and having advanced the adversary-system
explanation in its stead, when his work expressly indicates that he accepted the
explanatory importance of both these trial features.244
Since multiple explanatory principles are needed to account for the whole body
of law, attempts to isolate one explanation as the core idea driving evidence law are
futile at best. Nevertheless, studying the rationales behind evidence law reveals much
about both specific evidentiary doctrines and the working theory of the adjudicative
system itself. For example, to the extent that jury-control rationales have currency, the
system seems to doubt juries adjudicative competence; insofar as the courts
emphasize controls on perjury, they appear to assume that witness dishonesty is
rampant.245 Hence, as the rationales for evidentiary regulation are disputed, the
operating assumptions of evidence law are contested and unsettled.
Conclusion
This analysis has affirmed that evidence law and the jury are linked. Jury control
does not offer a unifying theory of common law evidence, since many evidence
doctrines are grounded in other policies, including concerns about the adversary
system and the risk of witness dishonesty. However, doubts about jury fact-finding do
ground some important features of evidentiary regulation. Rules aimed at
strengthening jury adjudication cannot be justified by a belief that juries are generally
incompetent, because such a global negative judgment finds little support in jury
241 See Twining, Theories of Evidence, supra note 14 at 157-58.
242 Wigmore, 1 Evidence, supra note 29 at 632.
243 Ibid. at 632-33.
244 See Morgan, Exclusionary Rules, supra note 144:
What then is the conclusion of the whole matter? Our exclusionary rules of evidence
are the resultant of several factors. … The adversary theory of litigation is directly
responsible for many of them; and judicial distrust of the jury for not a few. But the
dictum of the great Thayer that the English law of evidence is the child of the jury is,
it is suggested with the greatest deference, not more than a half-truth (ibid. at 258
[footnotes omitted]).
245 See Imwinkelried, supra note 8 at 1081.
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research. In fact, evidentiary regulation aimed at compensating for circumscribed,
demonstrable weaknesses in jury fact-finding only strengthens the jury system.
Whether a particular rule can be justified on jury-control grounds depends, first, on
the specific competencies required to evaluate the particular form of evidence and,
second, on what we know about jury psychology and behaviour. The real deficiencies
in jury performance may be particular and surmountable instead of general and
devastating.
The ongoing decline of the common law jury is of great interest to evidence
scholars. Jury trial has gone from a simple and routine means of disposition in the
seventeenth- and eighteenth-century English courts246 to a complex procedure that is
highly regarded but rarely used throughout the modern common law world. Today,
the vast majority of cases are dealt with through civil settlement or guilty pleas, and
those cases that do go to trial are usually adjudicated by judge alone, even in the
criminal context. In fact, the ordinary functioning of the justice system depends on
these alternative means of disposition, as jury adjudication has become so elaborate,
expensive, and time-consuming that resort to it is rare by necessity.247 Yet, even as
jury trial has declined, most lawyers, judges, and scholars have continued to approach
evidentiary issues from inside a framework that designates jury trial as the
paradigmatic form of adjudication.248 The real question for evidence scholars is
whether it is defensible to continue to focus so much attention on the jury.
246 Beattie, supra note 2 at 314-15.
247 See e.g. John H. Langbein, Torture and Plea Bargaining (1978) 46 U. Chicago L. Rev. 3 at 9;
Frankel, supra note 203 ([t]he jury trial … amounts in practice to a carefully husbanded ornament,
displayed on only a small fraction of its possible occasions. The effort to use it more would clog the
machinery beyond management at 20).
248 See e.g. Twining, Rethinking Evidence, supra note 5 at 201, 226-27; Damaka, Evidence Law
Adrift, supra note 3 at 26, 126-29.
