Is Criminal Expertise a Feature of Unsolved Sexual Assault Involving Theft?

Past studies on criminal expertise showed that some sexual offenders possess skills related to avoiding detection. An important question that remains unaddressed in the literature, however, is whether unsolved cases can be used as a "proxy" for expertise. The present study sought to provide the first empirical examination of criminal expertise in a sample of solved (n = 732) and unsolved (n = 309) stranger sexual assault cases involving theft. We used binary logistic regression to determine whether behavioral indicators of criminal expertise predicted case status. Findings showed that the most relevant factors related to case solvability were not related to detection avoidance strategies used by the offender, but rather, whether semen evidence was found at the crime scene and the number of sexual acts performed against the victim. Interestingly, cases involving fetish theft were also more likely to remain unsolved. Implications for theory and practice are discussed.