Dunkerton v The Queen

The case of *Dunkerton v The Queen* concerned an appeal to the High Court of Australia following a conviction for murder. The appellant, Dunkerton, had been found guilty of murder by a jury in the Supreme Court of Victoria and subsequently appealed to the Court of Appeal of Victoria, which dismissed his appeal. The central dispute revolved around the admissibility of certain evidence and the directions given to the jury by the trial judge.

The High Court was required to determine whether the trial judge had erred in admitting evidence of the appellant's prior convictions and whether the judge's directions to the jury regarding the use of this evidence were adequate. Specifically, the court considered whether the prejudicial effect of admitting evidence of prior convictions, which were similar in nature to the offence charged, outweighed its probative value. The court also had to assess whether the jury had been properly instructed on the limited purpose for which such evidence could be considered, namely, to establish a course of conduct or a system, rather than as evidence of propensity.

Gummow and Hayne JJ held that the admission of the evidence of prior convictions was an error. Their Honours reasoned that the similarities between the prior offences and the offence charged were not so striking as to establish a system or course of conduct that would justify admitting the evidence for that purpose. The court found that the prejudicial effect of the evidence was substantial, and the jury directions, while attempting to limit its use, were insufficient to overcome this prejudice. The risk that the jury would use the evidence as propensity evidence, suggesting that the appellant was guilty because he had committed similar crimes in the past, was too high.

Consequently, the High Court allowed the appeal, quashed the conviction for murder, and ordered a new trial.