The applicant, a complainant in a sexual assault prosecution, sought certiorari to review a preliminary inquiry ruling refusing to admit proposed expert evidence regarding the limited reliability of facial demeanour in assessing credibility.
The proposed expert intended to testify about social science literature suggesting that observing facial expressions does not meaningfully improve the ability to detect dishonesty.
The court applied the admissibility framework from R. v. Mohan and held that the preliminary inquiry judge did not err in declining to qualify the expert or admit the evidence, noting that the proposed opinion relied primarily on a literature review outside the expert’s field of direct research and lacked necessity.
The court further held that the complainant, as a third party whose Charter interests were directly affected, could seek certiorari review, but no jurisdictional error or error of law was established.