Commissioner of Police v Eaton

The Commissioner of Police (the appellant) appealed to the High Court of Australia against a decision of the Full Court of the Supreme Court of South Australia, which had allowed an appeal by Mr Eaton (the respondent) against a decision of a single judge of that court. The dispute concerned the validity of a search warrant issued under the *Controlled Substances Act 1984* (SA) and the admissibility of evidence obtained pursuant to that warrant.

The High Court was required to determine whether the search warrant was validly issued, specifically whether the information provided to the issuing officer was sufficient to establish reasonable grounds for believing that the respondent was in possession of a controlled substance. A further issue was whether, if the warrant was invalid, the evidence obtained should have been admitted under a provision of the *Evidence Act 1929* (SA) that allows for the admission of unlawfully or improperly obtained evidence if its probative value outweighs the degree of culpability of the impropriety or unlawfulness.

The Court held that the information before the issuing officer did not establish reasonable grounds for the belief required by the *Controlled Substances Act*. The information was based on an informant's tip that was not sufficiently corroborated or detailed to justify the intrusion of a search warrant. Consequently, the warrant was invalid, and the evidence obtained was unlawfully obtained. The Court then considered the admissibility of the unlawfully obtained evidence under the *Evidence Act* (SA). Applying the balancing test, the Court found that the probative value of the evidence did not outweigh the seriousness of the impropriety in its acquisition.

The High Court dismissed the appeal and affirmed the decision of the Full Court of the Supreme Court of South Australia, meaning the evidence obtained under the invalid warrant was excluded.