Evidence of Intoxication in Australian Criminal Courts: A Complex Variable with Multiple Effects

This article reports on the second stage of a national study of how the effects of alcohol and other drugs are treated by criminal laws and the criminal justice system. Based on a mixed methods analysis of more than 300 appellate court decisions from all Australian jurisdictions handed down in the period 2010–2014, we identify the multiple points at which legal significance is attached to evidence that the accused, the victim or a witness was ‘intoxicated’ at the time of the alleged commission of a criminal offence. Focusing on the rules and principles endorsed by appellate courts in relation to four key ‘sites’ of criminal justice decision-making — the admissibility of police interviews, the credibility and reliability of witness testimony, adjudication on the criminal responsibility of the accused, and determination of sentence for convicted offenders — we show that the impact of intoxication on the enforcement of the criminal law is complex. There is no single characterisation that can account for the multiple points at which intoxication may need to be assessed, and the divergent ways in which it can impact on adjudication. Depending on a range of site-specific and case-specific considerations, intoxication evidence may expand/contract the parameters of criminal responsibility, and it may yield higher or lower criminal penalties.