Bunning v Cross

Facts

The accused was charged with driving under the influence of alcohol. Police officers had administered a breathalyser test without first forming the required statutory suspicion that the accused was under the influence, thereby obtaining the evidence in breach of the relevant Western Australian legislation. The prosecution sought to rely on the breathalyser reading at trial.

Issues

1. Whether a trial judge has a discretion to exclude evidence obtained by law enforcement officers acting in breach of statute or in an unlawful manner. 2. If such a discretion exists, what principles govern its exercise.

Holding

The High Court held that Australian courts possess a discretion to exclude unlawfully or improperly obtained evidence, and that in the circumstances the breathalyser evidence should have been excluded. The discretion is not governed solely by relevance or prejudice but requires a balancing of competing public interests.

Ratio decidendi

Where evidence has been obtained by unlawful or improper conduct, a trial judge has a discretion to exclude it. That discretion is exercised by balancing the public interest in convicting the guilty against the public interest in not encouraging or appearing to condone unlawful conduct by those charged with law enforcement; neither interest is automatically paramount, and all relevant circumstances must be weighed.

Obiter dicta

Stephen and Mason JJ observed that the English rule in Kuruma v The Queen — that relevant evidence is admissible regardless of how it was obtained — should not be followed without qualification in Australia, and indicated that the seriousness of the impropriety and the ease with which the law could have been complied with are important considerations in the balancing exercise.

Significance

Bunning v Cross established the foundational Australian common law discretion to exclude improperly obtained evidence on public-interest grounds, a principle subsequently codified and refined in uniform evidence legislation and affirmed in later High Court decisions. It remains the leading authority on the policy rationale underlying exclusionary discretions in Australian criminal proceedings.

Key authorities

• Kuruma v The Queen Kuruma v The Queen [1955] AC 197distinguished
• R v Ireland R v Ireland (1970) 126 CLR 321considered
• McDermott v The King McDermott v The King (1948) 76 CLR 501considered
• Callis v Gunn Callis v Gunn [1964] 1 QB 495considered
• Jeffrey v Black Jeffrey v Black [1978] QB 490considered