R v Morrison

In the Supreme Court of South Australia, the accused, Morrison, was charged with the murder of Sheridan (Count 1), the attempted murder of Barty (Count 2), and wounding with intent to cause grievous bodily harm (Count 3). The central issue before the court was whether Morrison was mentally competent to commit these offences, given his history of consuming large quantities of methylamphetamine and exhibiting strange and unpredictable behaviour. The defence argued that Morrison's actions were due to an underlying mental illness exacerbated by the drug, while the prosecution contended that his psychotic symptoms were solely the result of amphetamine intoxication.

The court examined the psychiatric evidence presented by both sides. Three psychiatrists testified, with opinions varying on Morrison's mental state and the influence of his drug use. Dr Czechowicz believed Morrison's schizophrenia impaired his ability to understand his actions, whereas Drs Branson and Raeside concluded that his psychotic symptoms were a result of amphetamine intoxication, not mental illness. The court found that Morrison's psychotic symptoms were indeed caused by amphetamine intoxication, not by any mental illness, thus upholding the presumption of his mental competence.

After determining Morrison's mental competence, the court proceeded to the subjective elements of the offences. The findings indicated that Morrison consciously and voluntarily stabbed both victims. Although he intended to cause grievous bodily harm to Barty, there was insufficient evidence to prove he intended to kill her. Consequently, Morrison was found guilty of murder on Count 1, not guilty of attempted murder on Count 2, and guilty of wounding with intent to cause grievous bodily harm on Count 3. The court's final orders reflected these findings, confirming Morrison's convictions and acquitting him of the attempted murder charge.