What is the test for similar fact evidence in a criminal case?

The major difference between similar fact and discreditable conduct evidence is the manner in which the prior evidence generates probative value. Similar fact evidence, as its name implies, requires a degree of similarity between the allegation outside the scope of the indictment and the allegations encompassed by the indictment. The classic example is the “baby farming” case, Makin v. Attorney-General for New South Wales, [1894] A.C. 57. The finding of one baby in the backyard could have been a result of accident or natural causes but the finding of numerous babies suggested intentional conduct. It was very unlikely to be coincidence. The effect was to amplify and mutually support each allegation: see the brief discussion in R. v. Handy, 2002 SCC 56, [2002] 2 S.C.R. 908 (SC.C.) at para. 45.