Pfennig v The Queen

The appellant, Pfennig, appealed to the High Court of Australia against his conviction for the murder of Michael Black. The central issue on appeal concerned the admissibility of evidence relating to an admitted offence by the appellant 12 months after the murder, namely the abduction and sexual assault of a 13-year-old boy. The appellant argued that this evidence, referred to as the "Hyland evidence," was inadmissible as it relied solely on propensity reasoning, which is prohibited by established legal principles.

The High Court was required to determine whether the trial judge erred in admitting the Hyland evidence. Specifically, the Court had to consider whether evidence of a criminal disposition, in this instance, the appellant's propensity to kidnap and sexually assault young boys, could, of itself, possess the high degree of probative force necessary for admissibility, or if probative force must arise from some other characteristic or application of the evidence beyond mere propensity. The appellant contended that the authorities, including *Makin's* case and subsequent decisions like *Markby's*, have consistently required probative force to be demonstrated in ways other than simply showing a criminal propensity.

The trial judge had ruled that the Hyland evidence demonstrated not only the appellant's homosexual orientation but also his disposition towards young boys and his willingness to act on it through extreme means. The judge considered this evidence relevant to the question of whether the appellant was Michael Black's murderer, finding that it would be contrary to common sense to postulate two individuals with such a specific propensity and the means to act on it being in the same vicinity at the relevant time. The judge concluded that there was no rational view of all the evidence inconsistent with the appellant's guilt, relying on the shared propensity as a basis for improbability. However, the appellant argued that the judge's reasoning departed from the principles established in cases such as *Hoch v The Queen*, which require similar fact evidence to possess a high degree of probative force beyond mere propensity.