B v The Queen

The High Court of Australia considered an appeal by B against a conviction for murder. The dispute concerned the admissibility of certain evidence during B's trial, specifically evidence relating to B's prior convictions.

The central legal issue before the High Court was whether the admission of evidence of B's prior convictions, which tended to show that B had a propensity to commit the offence charged, was an error of law that rendered the conviction unsafe and unsatisfactory. The Court was required to determine whether the evidence was improperly admitted under the rules of evidence, particularly concerning the prohibition against admitting evidence of a person's character or previous convictions to prove that they acted in conformity with that character on a particular occasion.

Gummow and Hayne JJ held that the admission of evidence of prior convictions, where its primary relevance was to establish a propensity to commit the offence charged, constituted a miscarriage of justice. Their Honours applied the principle that evidence of prior convictions is generally inadmissible to prove guilt of a subsequent offence, as it risks the jury convicting the accused based on their past rather than the evidence presented for the current charge. The Court found that the prejudicial effect of this evidence outweighed any probative value it might have had, leading to an unsafe conviction.

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