McNamara v the King

The High Court of Australia considered an appeal by Glen McNamara against his conviction for murder and supplying a commercial quantity of methylamphetamine, alongside his co-accused Roger Rogerson. McNamara sought to introduce evidence that Rogerson had admitted to other homicides and violent acts, intending to use this to support his defence of duress. The trial judge excluded this evidence on the grounds that it was unfairly prejudicial to Rogerson.

The central legal issue before the High Court was whether the term "a party" in section 135(a) of the *Evidence Act 1995* (NSW) included a co-accused in a joint criminal trial. This section allows a court to refuse to admit evidence if its probative value is substantially outweighed by the danger of unfair prejudice to "a party". McNamara argued that the common law right to adduce admissible evidence of innocence, preserved by section 9 of the *Evidence Act*, necessitated a construction of section 135(a) that did not permit the exclusion of evidence solely because it was prejudicial to a co-accused.

The High Court reasoned that the *Evidence Act* was not intended to operate as an exhaustive code, and section 9(1) preserves common law principles unless expressly or by necessary intendment displaced. However, the Court found that the scheme of the *Evidence Act*, particularly section 135(a), applied to joint trials and that the term "a party" in that section encompassed a co-accused. The Court held that the discretion to exclude evidence under section 135(a) could be exercised to prevent unfair prejudice to any party, including a co-accused, in a joint trial. The exclusion of the evidence was therefore permissible.

The appeal was dismissed.