Toxicology and circumstances of death of homicide victims in New South Wales, Australia 1996-2005.

To determine the prevalence and circumstances of psychoactive substances amongst homicide victims, 485 consecutive cases autopsied at the NSW Department of Forensic Medicine (1/1/1996-12/31/2005) were analyzed. Substances were detected in 62.6% of cases, and illicit drugs in 32.8%. Alcohol, cannabis, opioids, and psychostimulants were most commonly detected. Alcohol and cannabis were both more prevalent amongst males. Mean ages were significantly younger for decedents who tested positive for a substance and for an illicit drug. Cases where death resulted from a physical altercation were more likely to have had alcohol and cannabis present. Illicit drugs were prominent amongst firearms deaths. The proportion of alcohol positive cases increased from 25.0% on Monday to 49.4% for Saturdays/Sundays. Alcohol was more common in incidents in the 0001-0600 h and 1800-2400 h periods. Psychoactive substances appear to substantially increase the risk of homicide, although there are important differences between drug classes in the circumstances of such incidents.