Collusion refers to the possibility that witnesses may have shared their stories with one another and, intentionally or accidentally, changed or tailored their stories in order that their testimony would seem more similar or convincing. Such collusion can destroy the potential probative value of testimony that would otherwise have seemed independent and compelling. Trial judges must not only consider the possibility of such collusion in relation to the admissibility of similar fact evidence as part of their gate-keeping function where there is an air of reality to such collusion, but must also consider the possibility of such collusion in simply assessing the reliability of the evidence of the witnesses.
In the final analysis, however, it is for the trier of fact to determine whether the testimony of the witnesses is reliable despite the possibility of collusion, or whether less weight, or no weight, should be given to the evidence which might have been influenced by the sharing of information.
William Poulos, Barrister