Partners in Crime

Abstract

Little is known about the characteristics of homicides committed by more than one perpetrator. This study examined the crime, victim, and perpetrator characteristics of individual homicides ( n = 84) versus multi-perpetrator homicides ( n = 40), according to official file information from two Canadian federal penitentiaries. Compared to multiple perpetrators, individual perpetrators were more likely to be older and to target female victims, and their homicides were more likely to contain reactive, sexual, and sadistic elements. Multi-perpetrator homicides tended to involve younger offenders, male victims, and instrumental motives. Psychopathic offenders were likely to act alone in committing sexual homicides and to involve an accomplice in other types of murders, but they typically committed gratuitous violence against women regardless of whether they acted alone or with a co-perpetrator. The findings indicate that individual and multi-perpetrator homicides have distinctive dynamics and can be differentiated during investigations.