Legal Issues of DNA Identification: A Canadian Perspective

Summary

At this time in Canada there have been only two completed cases involving the admissibility of DNA typing evidence. The first, R vs. Parent, involved the use of the polymerase chain reaction technique which excluded the accused; the other case, R vs. McNally involved the use of the first courtroom introduction of the restriction fragment length polymorphism technique resulting in a guilty plea before the jury trial was completed. In Canada, the admissibility standard is determined first by determining whether the evidence is relevant, and secondly by weighing the probative value against policy considerations. In addition, consideration of the admissibility of novel scientific evidence in the United States expressed as the Frye rule is necessary because of lack of Canadian law on the matter. Thus, the standard for admissibility of novel scientific evidence in Canada, and therefore the standard for admissibility of DNA typing evidence, is whether such evidence is relevant and helpful to the jury. The method for determining relevancy and helpfulness in the novel scientific evidence context involves factors of reasonable reliability and the dangers of confusing or misleading the jury and, to a lesser extent, the amount of time necessary to present such evidence. The parameters of the admissibility hearing are listed, and other derivative consequences of the use of relevancy/reliability standard in Canadian law are covered. Other legal issues, especially the role of the expert and the source of the opinion, and the admissibility of known bodily substances related to the presentation of DNA evidence are also discussed, and recent DNA case developments are cited.