Case comment: a critique of the Supreme Court of Canada’s use of statistical reasoning in R v. Mabior1.

This case comment critiques the Supreme Court of Canada’s decision in R v. Mabior. In Mabior, Chief Justice McLachlin affirmed the criminalization of human immunodeficiency virus (HIV) non-disclosure to sexual partners, and sought to clarify exactly when criminal sanctions apply. Citing expert evidence, McLachlin CJC held that criminal liability is appropriate for HIV non-disclosure when there is a ‘realistic possibility of transmission’ and that only condom use combined with antiretroviral therapy reduces this risk enough to preclude liability. Using the same expert evidence, I calculate the transmission rates underlying this argument and show that McLachlin CJC’s use of statistics results in logical contradictions and uncertain liability. I argue that her statistical approach is unworkable and I propose an alternative non-disclosure regime. [ABSTRACT FROM PUBLISHER]