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CED, an Overview of the Law — Similar Fact Evidence

Evidence law is a notoriously complex area of law. Some of its reputation is attributable to the difficult concept of hearsay evidence, which is generally inadmissible unless it falls within one of several established exceptions. Another difficult concept, which the CED tackles with aplomb, is similar fact evidence. The following post clearly and succinctly explains what similar fact evidence is, why it is potentially dangerous, and the circumstances in which it can be used. It is eminently helpful to those who seek a fuller understanding of evidence law.


BY: Peter Sankoff

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XI: Similar Fact Evidence

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XI.1: Introduction

See Canadian Abridgment: EVD.XV.6 Evidence | Character | Similar fact evidence

The common law rule concerning character evidence generally limits the manner in which parties can tender evidence of a person's prior disreputable conduct that is unrelated to the events before the court. The rule is especially strict where the defendant in a criminal proceeding is concerned.1 The most significant exception to the rule against evidence of bad character is similar fact evidence. This rule allows the prosecution to adduce evidence of criminal or improper acts2 committed by the defendant as evidence where it is similar to the acts being tried, and has probative value that outweighs its prejudicial effect. As a general rule, evidence of this sort will not be admissible where it is tendered merely to show that the defendant has a general propensity or disposition to commit the offence in question.3 However, where the evidence becomes more focused and specific to the incident before the court, the probative value of the evidence will increase to the point where it becomes admissible.4

Resolving the admissibility of similar fact evidence is a difficult exercise. The problem lies in the fact that this evidence is simultaneously probative and prejudicial. While a person's propensity to commit criminal acts is relevant, as people tend to act consistently with their known character, focus on this propensity may capture the attention of the trier of fact to an unwarranted degree. The potential for prejudice, distraction and time consumption from this evidence is considerable.5

Historically, evidence of this sort was treated in a categorical manner. Thus, in addition to being probative, the evidence of similar facts had to be clearly connected to an issue other than disposition or propensity.6 For example, evidence of similar facts was admitted where it could help establish guilty knowledge, intent, scheme or plan, motive, identity or another issue in the case. Today, the categorical approach has been discarded, and the sole concern is whether the evidence is more probative than prejudicial. In reaching a conclusion, the judge should assess a number of factors that assist in weighing the probative value of the evidence, and consider the manner in which prejudice can arise.7

XI.2.(a).(i): Balancing Probative Value and Prejudicial Effect--Generally

See Canadian Abridgment: EVD.XV.6.l Evidence | Character | Similar fact evidence | Miscellaneous

In assessing the admissibility of similar fact evidence, the court must consider the probative value in the circumstances and the extent to which it outweighs the likelihood that the trier of fact will become confused by the multiplicity of incidents and put more weight than is justified upon the similar acts — referred to as reasoning prejudice — and the possibility of a conviction being entered simply because of the defendant being a bad person — referred to as moral prejudice. Similar fact evidence is presumptively inadmissible, and the prosecution bears the burden of proving that the probative value of the evidence outweighs its prejudicial effect.1

Where the issue for which similar fact evidence is said to relate has ceased to be in dispute, as for example when the fact is admitted by the defendant, then the evidence is inadmissible.2

XI.2.(a).(ii): Requisite Degree of Similarity

See Canadian Abridgment: EVD.XV.6.a Evidence | Character | Similar fact evidence | Striking similarity

Where similar fact evidence is adduced, the court must evaluate the degree of similarity between the acts and decide whether the evidence is sufficiently similar to be admitted. The degree of similarity required depends upon the issues in the particular case, the purpose for which the evidence is sought to be introduced and the other available evidence.1 For example, where evidence of a similar act is tendered to prove the identity of a suspected offender, the evidence will only have sufficient cogency to be admitted where it is highly distinctive or unique, because otherwise the evidence is not useful to differentiate the defendant from other potential offenders.2 In contrast, where similar fact evidence is tendered for a less distinctive purpose, for example, to show a prior animus toward the victim, the acts need not be so similar to have a recognized probative value.3

XI.2.(a).(iii): Link to Defendant

See Canadian Abridgment: EVD.XV.6.c Evidence | Character | Similar fact evidence | Connection required

Before evidence may be admitted as evidence of similar facts, there must be a demonstrated link between the allegedly similar facts and the defendant. In other words there must be some evidence upon which the trier of fact can make a proper finding that the similar facts to be relied upon were in fact the acts of the defendant. In the absence of such proof, the similar acts have no relevance to the defendant's trial.1

XI.2.(a).(iv): Probative Value

See Canadian Abridgment: EVD.XV.6.l Evidence | Character | Similar fact evidence | Miscellaneous

The assessment of probative value requires a court to consider the similar facts carefully. As the facts become more focused and specific to circumstances described in the charge, the probative value becomes more cogent.1 It is essential for the court to identify the materiality of the evidence by ascertaining the specific purposes for which the evidence is being proffered.2 The court should ask the prosecution about the inference that is being sought from the evidence.3

In assessing the probative value of similar fact evidence, the court should consider a number of facts. The probative value of this evidence arises primarily from the improbability of coincidence between the defendant's alleged similar acts and the acts for which he or she stands charged. As such, the value of the evidence will tend to be enhanced where: (1) the similar acts are proximate in time to the offences before the court;4 (2) the acts are similar in detail;5 (3) there are multiple occurrences as opposed to just a single event;6 (4) the surrounding circumstances provide similarities;7 (5) there are distinctive features unifying the incidents;8 and (6) there are no intervening events that undermine the value of the evidence.9 Probative value of the evidence will be diminished where there is a strong potential for collusion between the witness providing evidence of the defendant's similar acts and the witness giving testimony on the offence for which the defendant is charged.10 These factors are not exhaustive and are merely a guide to the types of matters that may assist in determining the probative value of the evidence.11

While frailties in the weight of the evidence are normally left to the trier of fact, a court considering admissibility should also assess whether the similar acts, on the evidence available, are reasonably capable of belief.12

XI.2.(a).(v): Prejudice

See Canadian Abridgment: EVD.XV.6.l Evidence | Character | Similar fact evidence | Miscellaneous

Similar fact evidence can be prejudicial in a number of ways. First, the evidence can cause moral prejudice, which occurs where the trier of fact overlooks weaknesses in the prosecution case and convicts the defendant for being a bad person generally or as punishment for past immoral conduct.1 In assessing the moral prejudice of similar fact evidence, the court should consider the inflammatory nature of the previous acts.2

A second type of prejudice is reasoning prejudice, which refers to the distracting nature of similar fact evidence. In particular, this type of evidence may increase the complexity of the trial and divert the jury's attention away from the facts that form the offence for which the defendant stands charged.3 Cases in which the similar fact evidence requires numerous witnesses to prove or is disputed by the defendant have an increased potential for reasoning prejudice.4 Conversely, where the defendant admits the truth of the similar fact evidence, this type of prejudice is not a concern.5

In cases where the prosecution seeks to use evidence from one count of an indictment as similar fact evidence on a separate count, the court must also consider whether such use would unfairly lead the trier of fact to reject defences raised by the defendant in relation to one set of charges.6

While prejudice must be considered both in the context of jury and non-jury trials, reasoning prejudice is less of a concern in trials before a judge alone.7 Additionally, some of the factors commonly raised in relation to prejudice — most notably the risks of distracting the court and complicating the proceeding — are less relevant when the similar acts are raised in the context of a multi-count indictment where the trier of fact is being asked to use the facts of one count, which need to be admitted in any event, to support a conclusion in another.8

Where the defendant has been tried and acquitted of the facts providing the basis of the similar act, the evidence is generally regarded as being too prejudicial to be admitted at a subsequent trial.9 This rule does not apply where the alleged similar acts are the subject of a multi-count indictment, as the trier of fact is entitled to have a reasonable doubt about one count, and yet use it as proof — on the balance of probabilities standard — to establish another count.10

XI.2.(b): Similar Acts to Establish Identity

See Canadian Abridgment: EVD.XV.6.i Evidence | Character | Similar fact evidence | To establish identity

Although evidence of similar acts tendered to establish the identity of the offender is analyzed by using the usual balance of probative value and prejudicial effect, there are particular issues that can arise where this inference is sought. In this scenario, the trier of fact is effectively being asked to use similar acts to establish that the defendant is the person who committed a particular crime. This inference is made possible only if the high degree of similarity between the acts renders the likelihood of coincidence objectively improbable. Because of the risks involved, a court must be cautious before using propensity evidence in the context of identity.1

The admission of similar fact evidence on the issue of identity can be guaranteed in a number of ways. First, where the evidence shows a unique trademark or signature that is present in the offence for which the defendant is being tried, the evidence will normally be sufficiently probative to warrant admission. In the alternative, where a number of significant similarities between the acts exist, they may cumulatively be cogent enough to pass the threshold test of admissibility.2

Similar facts can be admitted to show that a particular group of persons committed the act for which the defendant is on trial. In these circumstances, the court must first find that the act is sufficiently distinctive to allow the inference that the same group or gang committed both acts. Still, before permitting this evidence to be tendered against a particular defendant, the court must also be convinced that the similar act has enough probative value with regard to the individual member to warrant admission.3

XI.2.(c): Similar Facts to Establish Motive

See Canadian Abridgment: EVD.XV.6.h Evidence | Character | Similar fact evidence | To demonstrate motive

Where similar facts are tendered to establish motive, the determination of admissibility is somewhat different, as the probative value of the evidence does not arise from similarity. Evidence of prior conduct of the defendant toward a victim may be dissimilar but still compelling as far as motive is concerned.1 Nonetheless, not every act of past misconduct is admissible. The court must consider whether the evidence provides the trier of fact with real insight into the background and relationship between the defendant and victim and provides a bona fide theory of motive.2

XI.2.(d): Instructing the Jury

See Canadian Abridgment: EVD.XV.6.l Evidence | Character | Similar fact evidence | Miscellaneous

When similar fact evidence is tendered in a jury trial, the trial judge must instruct jurors about the limited purpose for which they may use the evidence, and in particular that the evidence is not to be used to infer that the defendant is a person with a general disposition to engage in criminal conduct, and thus the type of person likely to have committed the offence. This kind of instruction is essential to avoid the moral and reasoning prejudice that can arise from this sort of evidence.1 The Ontario Court of Appeal has also suggested that juries be told not to punish the defendant for past misconduct by reaching a guilty verdict for the offences charged.2

Juries must also be instructed not to use evidence of similar facts unless they are satisfied that the similar fact incident occurred and the defendant was the person who committed it.3 Juries should also be advised about any major frailties with the evidence, including the possibility of collusion between witnesses.4

A jury instruction is not necessarily required where evidence of similar fact has value in establishing the motive of the defendant. For example, where prior threats made by the defendant toward the victim are admitted to show that there was a motive to commit a particular offence, a limiting instruction would make no sense. Effectively the jury would have to be told that it could not use the evidence to establish a general propensity on the part of the defendant to act improperly, but that it could use the evidence to provide a motive for the defendant's actions toward the victim.5

Where similar fact evidence is being used to prove identity in a multi-count indictment, special instructions are required. First, the jury must be told that it may find from the evidence that the offences were committed by the same person, and the judge should review the similarities between the offences. Second, the judge should instruct the jury that if it concludes that the same person committed more than one of the offences, then the evidence on one count may be used to assist in deciding whether the defendant committed the offence charged on another count. Third, the jury must be warned to use the offence only for the appropriate purpose, and not to infer a general disposition. Finally, the jury must be instructed only to convict on a count where jurors are convinced beyond a reasonable doubt that the defendant is guilty.6

XI.2.(e): Timing

See Canadian Abridgment: EVD.XV.6.l Evidence | Character | Similar fact evidence | Miscellaneous

Admission of similar fact evidence requires that the prosecution identify the material issue to which the evidence is said to relate.1 In some cases, the prosecution will wish to admit such evidence to rebut a defence that might be open to the defendant. The difficulty in doing so lies in the fact that the defence might not actually be raised, and if the judge admits the evidence as part of the prosecution case, the defendant might be prejudiced. On the other hand, if the prosecution does not tender the evidence, it might be adjudged to have split its case.2

Where possible, the judge should determine the admissibility at the outset of the trial, but in some cases it may prove necessary to delay ruling on admission until sufficient evidence has been tendered to allow for an informed decision to be made.3

XI.3: Civil Proceedings

See Canadian Abridgment: EVD.XV.6.j Evidence | Character | Similar fact evidence | Civil cases

As discussed previously in this Title, the character of a party to a civil action is generally inadmissible.1 There is an exception for evidence of similar acts, however, which will tend to be admitted where the evidence is logically probative to an issue and not unfair to the parties. While evidence of this sort will not automatically be admitted, because of the reduced concern about prejudice in civil trials it is not approached with the same scrutiny demanded in criminal proceedings.2 Nevertheless, as in criminal trials, evidence going to show a general disposition alone is an insufficient basis to admit similar act evidence. The courts tend to apply the same criteria used in criminal proceedings — albeit in a somewhat relaxed matter — to resolve admissibility.3

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