The Use of Phallometric Evidence in Canadian Criminal Law

The use of phallometric evidence by Canadian criminal courts has steadily increased since the early 1980s. Phallometry was initially considered by courts to be a potentially useful tool in the determination of accused persons' culpability; however, its contemporary use is limited to the postconviction contexts of sentencing and dangerous and long-term offender applications, as one of several means of diagnosing offenders, determining recidivism risk, and assessing treatment prospects. We provide an overview and assessment of the use of phallometric evidence by Canadian criminal courts and conclude that its contemporary application appears to be consistent with the expert psychiatric consensus on its proper role and function in the forensic context. We further identify potential difficulties associated with the adequacy of offenders' consent and the occasional divergence of expert opinion about the reliability and validity of phallometry for diagnosis and risk assessment.