Is the sexual murderer a unique type of offender? A typology of violent sexual offenders using crime scene behaviors

The empirical literature on sexual homicide has posited the sexual murderer as a unique type of offender who is qualitatively different from other types of offenders. However, recent research has suggested that sexual homicide is a dynamic crime and that sexual assaults can escalate to homicide when specific situational factors are present. This study simultaneously explored the utility of the sexual murderer as a unique type of offender hypothesis and sexual homicide as a differential outcome of sexual assaults hypothesis. This study is based on a sample of 342 males who were convicted of committing a violent sexual offense, which resulted in either physical injury or death of the victim. A series of latent class analyses were performed using crime scene indicators in an attempt to identify discrete groups of sexual offenders. In addition, the effects of modus operandi, situational factors, and offender characteristics on each group were investigated. Results suggest that both hypotheses are supported. A group of offenders was identified who almost exclusively killed their victims and demonstrated a lethal intent by the choice of their offending behavior. Moreover, three other groups of sex offenders were identified with a diverse lethality level, suggesting that these cases could end up as homicide when certain situational factors were present.