DKA v The State of Western Australia

DKA v The State of Western Australia is a case that concerns the admissibility of propensity evidence in criminal proceedings. The dispute arose from the appellant's conviction for serious sexual offences, where the State sought to introduce evidence of the appellant's inappropriate conduct of a sexual nature towards other witnesses. The issue before the court was whether the proposed propensity evidence had significant probative value and whether its admission would cause an unfair trial. The court was required to decide whether the evidence met the criteria set out in section 31A of the Evidence Act, specifically whether it had significant probative value and whether the probative value outweighed the risk of an unfair trial.

The court carefully considered the nature and relevance of the evidence in question, applying the statutory framework provided by section 31A. The court held that propensity evidence must be capable of rationally affecting, to a significant extent, the assessment of the probability of the existence of a fact in issue. It also noted that the term "significant" in "significant probative value" connotes "important" or "of consequence." The court found that the evidence in question did not have significant probative value as it was not sufficiently relevant to the facts in issue. Furthermore, the court held that even if the evidence had significant probative value, the risk of an unfair trial would outweigh the probative value, as the evidence could unduly prejudice the jury against the appellant.

In light of the court's findings, the appeal was allowed, and the convictions were quashed. The court emphasised the importance of striking a balance between the probative value of evidence and the risk of an unfair trial, and it held that in this case, the risk of an unfair trial was too great to justify the admission of the propensity evidence. The court's decision highlights the stringent requirements that must be met for propensity evidence to be admitted in criminal proceedings.