Leach v The Queen

Leach (the applicant) was convicted of murder and sentenced to life imprisonment. He appealed his conviction to the High Court of Australia, arguing that the trial judge had erred in admitting certain evidence and in directing the jury on the issue of self-defence. The Queen (the respondent) was represented by the Crown.

The High Court was required to determine whether the trial judge had erred in admitting evidence of the applicant's prior convictions and prior bad character, and whether the jury directions on self-defence were adequate and properly explained the onus of proof. Specifically, the court considered whether the prejudicial effect of the evidence of prior convictions outweighed its probative value, and whether the jury had been sufficiently instructed on the subjective and objective elements of self-defence.

The High Court held that the admission of the applicant's prior convictions was an error, as the evidence was not relevant to any issue in the trial and its prejudicial effect was substantial. The court also found that the jury directions on self-defence were inadequate, particularly concerning the onus of proof and the subjective belief of the accused. The reasoning applied was that for evidence to be admissible, it must be relevant and its probative value must outweigh its prejudicial effect. Furthermore, jury directions must be clear and comprehensive, ensuring the jury understands all elements of the offence and any defences.

The High Court allowed the appeal, quashed the conviction, and ordered a new trial.