Juvenile sexual abusers commit a significant proportion of the sexual offenses perpetrated in the United States each year. Researchers have identified several variables related to the etiology of sexual offending behavior in adolescent males. For example, there is evidence that both trauma and deviant sexual arousal have been independently linked to sexual aggression committed by adolescent sexual abusers. However, an etiological model that accounts for all of the variance with regard to sexual offending behavior or sexual recidivism in Juvenile Sex Offenders (JSOs) has not yet been developed. In the current study, a pre-existing data set of adjudicated JSOs who were incarcerated for sexual offenses at the time data was collected was used to examine several constructs. Self-report data about deviant sexual arousal and the youths\u27 trauma histories were among the data that were collected from this sample, and were used as the two independent variables in the current study. Total number of victims, total force used in the sexual offense(s) and perpetration severity were used to represent three facets of sexual aggression, the dependent variable in the current study. The hypothesis underlying the current study was that deviant sexual arousal affects the interaction between a youth\u27s trauma history and the extent to which he engaged in sexual aggression. In order to test this hypothesis a mediator analysis was performed to assess the amount of variance in the relationship between trauma and each of the three variables representing sexual aggression that can be explained by the presence of deviant sexual arousal. Deviant arousal added significantly to the amount of variance in both total force and number of victims after accounting for trauma in each model; these were additive models. Deviant arousal mediated the relationship between the youth\u27s trauma history and perpetration severity
