Matricides in South Australia - a 20-year retrospective review

A 20-year retrospective review of files at Forensic Science SA, Adelaide, Australia was undertaken for cases of matricide occurring between the years 1985 and 2004. A total of 11 cases were identified: 10 males and 1 female. The victims were aged between 42 and 83 years (mean=61 years) and the perpetrators were aged between 15 and 53 years (mean=28.7 years). In all 11 cases weapons such as blunt objects (N=5), knives (N=5), firearms (N=3), or ligatures (N=1) were involved in the assaults, with injuries inflicted by the weapons causing death in 10 cases. In five cases trauma was caused by more than one injurious agent/action; e.g. there was evidence of immersion and burning in two cases. In four cases there were multiple (>10) significant injuries inflicted by perpetrators suffering from schizophrenia (N=2), 'mental impairment' (N=1) and a 'combination of psychiatric disorders' (N=1). One perpetrator committed suicide after killing his mother. Six of the ten surviving perpetrators were found not guilty of murder on the grounds of mental illness or impairment, and one perpetrator had the charge reduced from murder to manslaughter due to underlying mental conditions that included previous brain injury. Matricides are uncommon forms of homicide that have similar features in most communities studied. Intra-familial tensions with underlying psychiatric illness in the perpetrator are common findings.