Collusion

R. v. Clause, 2016 ONCA 859:

[81]        Collusion can arise both from a deliberate agreement to concoct evidence, as well as from communication among witnesses that can have the effect, whether consciously or unconsciously, of colouring and tailoring their descriptions of the impugned events: R. v. B. (C.) (2003), 167 O.A.C. 264, [2003] O.J. No. 11 (C.A.), at para. 40. As this court noted in R. v. F.(J.) (2003), 177 C.C.C. (3d) 1, [2003] O.J. No. 3241 (C.A.), at para. 77, the "reliability of a witness's account can be undermined not only by deliberate collusion for the purpose of concocting evidence, but also by the influence of hearing other people's stories, which can tend to colour one's interpretation of personal events or reinforce a perception about which one had doubts or concerns."

[82]        In R. v. Burke, [1996] 1 S.C.R. 474, the Supreme Court addressed how to deal with the issue of possible collusion outside the context of similar fact evidence. The court stated, at para. 45:

On the assumption that the evidence is admissible, I am prepared to adopt the more conventional approach which would leave it to the trier of fact to determine what weight, if any, is to be given to evidence that is alleged to have been concocted by means of collusion or collaboration. Under this approach, the trier of fact is obliged to consider the reliability of the evidence having regard to all the circumstances, including the opportunities for collusion or collaboration to concoct the evidence and the possibility that these opportunities were used for such a purpose.

[83]        Summarizing the jurisprudence dealing with the possibility of tainting by collusion in the context of the treatment of similar fact evidence, this court stated in R. v. F.(J.), at para. 86, that once evidence is admitted, "the jury must still be warned to assess the evidence carefully and to consider whether it can be considered reliable given the possibility of deliberate or accidental tainting by collusion among the witnesses" (citation omitted).

Of the Law Societies of Upper Canada and Nunavut