Classifying Serial Sexual Murder/Murderers

Abstract

Keppel and Walter’s (1999) classification system for serial sexual murder/murderers is sometimes used as the basis for generating offender profiles despite the fact that it has yet to be empirically validated. This model assumes that serial sexual murder/murderers can be classified into four categories—power-assertive, power-reassurance, anger-retaliation, and anger-excitation—according to the degree of anger and power exhibited by the offender in their criminal and noncriminal lives. Within the current study, assessing the validity of this model involved examining the crimes and backgrounds of 53 serial sexual murderers to determine if the categories proposed by Keppel and Walter could be identified. Proximity Scaling was used to examine the degree of co-occurrence between each and every behavior/characteristic. No evidence of highly co-occurring behaviors/characteristics from Keppel and Walter’s proposed categories was found, indicating that the classification system is potentially invalid. Results are discussed in terms of their theoretical and practical implications.