The modus operandi of serial and nonserial sexual murderers: A systematic review

•Sexual murder possesses specific choice-structuring properties and a limited number of crime scripts.•SSMs' modus operandi reflects sadistic sexual fantasies, sexual sadism, and organization.•NSMs' modus operandi is shaped by anger. They are impulsive and extremely violent murderers.•The number of victims per murderer may be a good proxy measure of the type of sexual murderer.

The goal of this current systematic review was to describe the characteristics of the modus operandi of serial and nonserial sexual murderers, and the contextual and situational factors associated with them. It analyzes detailed data on 1836 sexual murderers (serial sexual murderers = 176; nonserial sexual murderers = 1660) taken from 45 empirical descriptive studies carried out between 1985 and 2013. In order to better characterize serial sexual murderers (SSMs) and nonserial sexual murderers (NSMs), four categories of variables were established: precrime variables; crime scene and modus operandi variables; postcrime variables; and victimology variables. Sexual murder possesses specific choice-structuring properties, and interactions between internal constraints and external constraints produce a limited number of crime scripts. SSMs' modus operandi reflects sadistic sexual fantasies, sexual sadism, and organization. SSMs plan their murders in order to make them as congruent as possible with their fantasies. NSMs' modus operandi is the result of an explosion of anger. These sexual murderers are impulsive and extremely violent, and use sexual murder to diminish their internal tension