In similar fact evidence cases, at the admissibility stage, the trial judge’s main task is to weigh the probative value of the evidence against its potential prejudicial effect. The possibility of collusion may significantly affect this balancing.See R. v. Wilkinson, 2017 ONCA 756 (CanLII), at para. 29. The theory of similar fact evidence turns largely on the improbability of coincidence. Collusion, by offering an alternative explanation for the "coincidence" of evidence emanating from different witnesses, destroys its probative value, and therefore the basis for its admissibility. R. v. Shearing, 2002 SCC 58 (CanLII),Shearing, at para. 40. Accused to Establish an Air of Reality to the Allegation of Collusion The dividing line between cases in which collusion is a live issue, and cases in which it is not, is the presence of an “air of reality.” As Binnie J. held in Handy,2002 SCC 56 (CanLII), at para. 111: “The issue is concoction or collaboration, not contact. If the evidence amounts to no more than opportunity, it will usually best be left to the jury.” Crown must then disprove collusion on balance Although collusion is a feature of probative value, it is singled out for special consideration at the admissibility stage. The Crown must disprove the possibility of collusion. Where, there is some evidence of actual collusion, or at least an "air of reality" to the allegations, the Crown is required to satisfy the trial judge, on a balance of probabilities, that the evidence of similar facts is not tainted with collusion. That much would gain admission. Handy, at para. 112. If this threshold test is passed, the jury must determine for itself what weight, if any, to assign to the similar fact evidence. Shearing, at para. 42. Inadvertent Collusion Collusion may
Similar Fact EvidenceEvidence of an accused’s discreditable conduct, apart from that alleged conduct which forms the basis of the charges, is presumptively inadmissible at trial, as evidence tendered solely to show a general disposition or a mere propensity to act or to think or to feel in a particular way is inadmissible.However, evidence of other discreditable conductmay be admitted where the prosecution establishes, on a balance of probabilities, that in the context of a particular case the probative value of the evidence in relation to a particular issue outweighs its potential prejudice and thereby justifies its reception. Probative value is increased by there being a sufficiently strong connection between the past discreditable conduct and the contested facts at trial.The considerable passage of time between those two sets of facts affects the probative value (and hence the admissibility) of the proffered evidence of other discreditable conduct, as the inferences which can be drawn from that conduct generally becomes more tenuous with the passing of time. In R. v. P.M.C, the Court of Appeal for Ontario held that while there were certainly similarities between the alleged acts of the adult accused and his acts of sexual impropriety committed as a young offender (acts occurring 30 years apart), those similarities were not so striking or apparent to overcome the obvious problems posed by the passage of time, and the difficulty of attributing significance to the acts of an young offender when considering the guilt of an adult and vice versa: R. v. P.M.C, 2016 ONCA 829 at para 25.