Substance use among Italian serial-murderers: correlates with type of aggressive behaviour

Abstract

The association between substance use and aggressiveness is widely agreed upon. Although alcohol and drug use among serial murderers has been investigated, no study has examined the correlates of specific substance use, as for the modalities of homicidal behaviour. The present paper verified the possible links between different substance use and homicidal behaviour in a sample of 53 italian serial murderers, who slaughtered a total of 232 victims, along the hypothesis that homicidal behaviours vary according to the type of substance, with clear implications on grounds of criminal profiling. From biographical sources it was possible to ascertain the presence and typology of lifetime regular substance use for seventeen subjects, especially alcohol, opiates and stimulants with a high rate of polyabuse. A comparison between substance abusing groups was performed by variables of homicidal behaviour. Results show that the lifetime use of any substance is linked with the trend to use blunt weapons for the killings. A history of opiate use is related to killing female victims, and killing females only in one's series. Lifetime opiate users tend to display signs of disorganized behaviour. Results thus seem to indicate the correlation between lack of aggression planning and some sex-specific hostile drive: it can be hypothesized that the combination between a psychopathologic disposition and the destabilizing effect of chronic opiate intoxication may render subjects prone to a special kind of aggressive behaviour, mainly addressed or emerging against females.