R v Awer and the Dangers of Science in Sheep's Clothing

Canadian courts regularly affirm their commitment to gatekeeping scientific evidence, saying it is fundamentally important to determine the admissibility of such evidence before it can impact the ultimate decision. The significance of gatekeeping is underscored by the fact that unreliable science has been at the heart of many high-profile wrongful convictions. In fact, a leading study demonstrated that invalid forensic science was present in approximately 60% of wrongful convictions. But while pronouncements of commitment to gatekeeping are laudable, they are empty if not rigorously followed. In fact, a recent trend has seen a more permissive approach take hold, with scientific evidence characterized as “specialized knowledge”, and evaluated primarily on the basis of the expert's qualifications. Exacerbating this issue, trial judges sitting alone are regularly more permissive in their gatekeeping role than those sitting with a jury. Both trends, which insulate scientific evidence from scrutiny, came to a head in a recent 2-1 decision of the Alberta Court of Appeal. In this case, R v Awer, the Crown's expert presented a theory about DNA transfer supported by his own previous informal observations and journal articles penned by a police crime lab (and of questionable reliability). Despite the Crown's characterization of the expert's testimony as science, the majority of the Court of Appeal characterized it as specialized knowledge, and refrained from any inquiry into how the expert performed his tests, his sample size, or any controls for bias. Similarly, despite characterizing the journal articles as science, the majority did not scrutinize them at all. As a result, two highly prejudicial forms of evidence were allowed to impact a critical legal decision with no analysis as to their reliability