Similar Fact Evidence

Evidence 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.