THE (ONGOING) JOURNEY TO RELIABLE EXPERT EVIDENCE
Keywords:evidence, testimony, expert, witness, social science, forensics, specialized, knowledge, scientific evidence, R v Abbey, criminal trials, drug expertise, gang expertise, police expertise, psychology and law
Canadian courts draw a tenuous distinction between expert scientific evidence and what they characterize as specialized knowledge gained through the expert witness’ experience, training, and research. This characterization is based on unclear criteria and has significant consequences. Notably, specialized knowledge regularly receives considerably less scrutiny than that which is characterized as science, while still often serving as powerful inculpatory evidence in criminal trials. Moreover, specialized knowledge is often provided by figures that carry an air of authority, like police officers and scientists. This article focuses on the leading opinion on specialized knowledge, the Court of Appeal for Ontario’s decision in R v Abbey.
An analysis of Abbey’s application to three fields of contested specialized knowledge (including the evidence the Abbey Court admitted, but which fresh evidence revealed as fundamentally unreliable) provides two general insights. First, while Abbey could be interpreted as providing for a flexible and probing analysis of all expert evidence, courts have often relied on it to justify giving almost no scrutiny to specialized knowledge. Second, this review of the post-Abbey jurisprudence suggests that scrutiny focused on the transparency of the expert’s data and analysis, and whether that analysis can reliably be applied to the relevant factual question, may provide a valuable way to evaluate expertise.