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Assumptions Underlying Behavioral Linkage Revisited: A Multidimensional Approach to Ascertaining Individual Differentiation and Consistency in Serial Rape

NCJ Number
Date Published
May 2015
194 pages
This study empirically tested the theory that the existence of a serial rapist can be determined by crime-scene evidence from a number of rapes that show consistency in offender behaviors, thus suggesting that a single individual has committed multiple rapes.

Using individual differentiation analysis, the study confirmed that sexual offenses can be differentiated based on the degree and subtype of the behavioral dimensions or methods used to control the victim, the use of violence, and patterns of sexual activity in the rape. The analysis of consistency in these behaviors within and across these dimensions at various crime scenes determined that although none of the offenders exhibited total consistency across behavioral dimensions, a subsample of offenders remained fully consistent in at least one of the behavioral measures. In addition, of those who were not consistent, the vast majority manifested an identifiable trajectory of change. Findings are discussed in the context of psychological theories of behavioral consistency and the practical aspects of advancing the usefulness of behavioral linkage from crime scenes. The dataset used for this study consisted of 30 rape series, all committed by male offenders acting alone. They were responsible for 192 distinct sexual assault incidents. The data were obtained from closed, fully adjudicated State and local cases of serial rape. Methods of statistical analysis are described in detail. 26 tables, 24 figures, approximately 180 references, and appended supplementary information

Date Published: May 1, 2015