A review of international literature examining the link between mental disorder and violent criminal behaviour suggests that, although a small number of mentally disordered individuals engage in violent criminal behaviour, the vast majority is unlikely to commit homicide. This study, based on available information in police reports, found that only 4.4 per cent of Australian homicide offenders were recorded as suffering from a mental disorder. This would seem to indicate that the prevalence of mental disorder amongst homicide offenders is significantly less than amongst the general population, although a more rigorous clinical assessment of the offenders might have identified more cases of this nature.
Contrary to public perceptions of mentally disordered persons, the present study has found no evidence to support the notion that mentally disordered offenders are more likely to kill strangers in public places for no apparent reason. In reality, this study has found that mentally disordered offenders who commit a homicide are more likely to victimise a family member in or at some private residence.