Mitchell v The King; Rigney v The King; Carver v The King; Tenhoopen v The King

The High Court of Australia considered appeals from convictions for murder brought by Mitchell, Rigney, Carver, and Tenhoopen. The central dispute concerned the admissibility of evidence obtained through the use of a "drug dog" and the proper application of the exclusionary rule in relation to such evidence. The appellants argued that the evidence obtained by the drug dogs was unlawfully obtained and therefore inadmissible.

The primary legal issue before the Court was whether the common law exclusionary rule, which mandates the exclusion of evidence obtained unlawfully, applied to evidence obtained by the use of drug detection dogs. This involved determining whether the use of drug dogs constituted an unlawful search or seizure at common law, and if so, what the consequences were for the admissibility of the evidence they detected.

The Court held that the use of drug detection dogs does not, in itself, constitute a search or seizure at common law. Rather, the dog's alert is merely an indication that a search may be warranted. The Court reasoned that a search only occurs when a police officer physically intrudes upon a person or their property with the intention of finding something. The dog's alert does not involve such an intrusion. Therefore, the common law exclusionary rule, which is engaged by unlawful searches or seizures, was not triggered by the use of the drug dogs in these circumstances. The Court affirmed that the admissibility of evidence obtained through drug dogs is governed by statutory provisions, not the common law exclusionary rule.

The appeals were dismissed.