Does Mohan matter in child sexual abuse cases

R v. Mohan (1994) was a significant Supreme Court ruling pertaining to the admissibility of expert testimony in courts of law. In Mohan, the Supreme Court Justices ruled that the following are necessary criteria for considering the admissibility of expert evidence: (1) relevance of the testimony, (2) necessity in assisting the trier of fact, (3) the absence of any exclusionary ruling, and (4) a properly qualified expert. Although Mohan offers criteria for the admissibility of expert scientific testimony, has the ruling been applied uniformly? I conducted a review of the Canadian legal search engine Quicklaw for cases involving the admissibility of psychological testimony in court. Of particular interest were those cases invoking social science expertise in the area of sexual abuse. In order to assess properly the impact of the Mohan ruling on psychological testimony one needs to examine several factors. First, a review of higher court judgments pre-Mohan was conducted to determine what criteria were being used when judges were assessing the admissibility of expert evidence before this monumental ruling. These criteria were compared to those that had since been utilized to determine an expert's admissibility since Mohan. Second, I identified when and how the Mohan criteria are applied in order to help predict whether judges would admit/reject psychological testimony in cases of alleged child sexual abuse. Therefore, I compared those cases citing the Mohan ruling in order to exclude psychological testimony to those citing this ruling in order to admit expert testimony. I analyzed their content in order to find thematic patterns for admitting, and not admitting, experts to testify on behalf of the defense and prosecution. Specifically, I wanted to understand how judges determine whether they will admit a psychologist to testify in sexual abuse cases. Then, I compared the types of testimony that were admitted and rejected. Finally, I considered the characteristics of the court/case, expert and complainant that might have affected these rulings.