A crime scene approach to distinguishing sexual murderers

Previous studies have identified two main types of sexual murderers: ‘angry’ and ‘sadistic’. Similar to the ‘organized murderer’ of the FBI, the sadistic sexual murderer has been described as likely to inflict mutilation, use restraints, humiliate, and force anal sex on the victim. All four behaviours are found on several sadism scales developed to measure sadism in sex offenders. This study compares crime-scene characteristics for sexual murderers who have used these four behaviours associated to sexual sadism. Using a sample of 85 Canadian sexual murderers, logistic regression models were created to identify potential differences between sexual murderers who adopted such “sadistic” behaviours and those who did not. Findings, for example, show sexual murderers who have inflicted mutilation on the victim are more likely to pre-select and pre-meditate the crimes. Findings will be discussed in light of the literature on sexual sadism and the implications for the investigation of these crimes.