Nielsen v The Queen

The applicant, Grahame Simon Nielsen, sought special leave to appeal to the High Court of Australia from a decision of the Queensland Court of Criminal Appeal. The dispute concerned the defence of diminished responsibility in a murder trial. The applicant argued that the jury should have been permitted to consider the transient effects of alcohol in conjunction with a pre-existing mental disorder when determining whether the defence of diminished responsibility applied.

The central legal issue before the High Court was whether, in assessing diminished responsibility for an accused suffering from a pre-existing mental disorder, a jury could take into account the transient effects of alcohol on that mind. This question was considered to be of public importance given the frequent relevance of diminished responsibility in murder trials, and the limited availability of this defence in Australian jurisdictions at the time.

The applicant's legal team contended that the trial judge had erred by directing the jury to disregard entirely the question of alcohol when considering diminished responsibility. This direction, while consistent with existing authority in England and Queensland, was challenged on the basis that the applicant's mental abnormality was a composite of his depressive illness, chronic post-traumatic stress disorder, and the effects of alcohol intake. The applicant conceded that the transient effects of alcohol alone were not sufficient for the defence, but argued that their interaction with the pre-existing conditions was a relevant consideration.