Graat V. The Queen

Graat v. The Queen, 2 S.C.R. 819, is the leading case decided by the Supreme Court of Canada on the admissibility of opinion evidence. The Court held that lay persons may give opinion evidence, which is normally reserved only for expert witnesses, where the opinion so closely infers fact that it is a "compendious statement of fact". The determination is left to the discretion of the trial judge.