THE COLLATERAL FACTS RULE
Collateral matters have been defined as matters which are not determinative of an issue arising in the pleadings or indictment, or not relevant to matters which must be proved for the determination of the case. The general rule respecting collateral fact evidence is that one cannot impugn a witness’s credibility by contradicting the witness on matters which are collateral, even in a case where the core issue is credibility. As one court has put it: “Collateral evidence is evidence which depends for its relevance on the fact that it contradicts a witness.” R. v. H. (J.), 2014 NLCA 25 (CanLII), at para 33. The Reason for the Rule The collateral facts rule prohibits the introduction of evidence for the sole purpose of contradicting a witness’ testimony concerning a collateral fact. The rule seeks to avoid confusion and proliferation of issues, wasting of time and introduction of evidence of negligible assistance to the trier of fact in determini...