From crime scene actions in stranger rape to prediction of rapist type: single-victim or serial rapist?

The differences in crime scene actions in cases of stranger rape committed by convicted offenders were examined between 31 single-victim rapists and 35 serial rapists. Data were collected from police files, court verdicts, psychiatric evaluations, and criminal records. Findings indicate that the serial rapists were more criminally sophisticated than the single-victim rapists, during their first and second rapes. The single-victim rapists were significantly more likely to engage in the interpersonal involvement behavior of kissing the victim, and to engage in pre-assault alcohol use, than the serial rapists. There was, however, no significant difference in physically violent or sexual behaviors. To investigate the possibility of predicting rapist type, logistic regression analyses were performed. Results indicate that three behaviors in conjunction, kissed victim, controlled victim, and offender drank alcohol before the offense, predicted whether an unknown offender is a single-victim or serial rapist with a classification accuracy of 80.4%. The findings have implications for the classification of stranger rapists in offender profiling.