Relying on Demeanour Evidence to Assess Credibility during Trial - A Critical Examination

Abstract

Demeanour evidence is relied on by the justice system in one of the most important assessments at a trial, namely to assess the credibility of witnesses including complainants and accuseds. This use has also been the source of recent controversy in the case of R v NS where a sexual assault complainant was ordered to remove her niqab before she would be allowed to testify. This paper examines the common law assumption that witnesses in common law criminal courts are required to testify with their faces visible and the origins of this assumption. This paper argues that based on strong social science research the reliance on demeanour cues can be a distracting and unreliable method to assess credibility and increases the potential for wrongful prosecutions and convictions, reduced access to justice for marginalized groups and has a detrimental effect on the truth-seeking function of a trial as whole.

Keywords: demeanour evidence, credibility assessments, Niqab, face-to-face confrontation, full answer and defence, cross-examination, deception detection