In this study, the relationship between situational/developmental factors and the use of violence during sexual offenses is investigated. A sample of 293 adolescent sex offenders in treatment was used for that purpose. Official sources of information were used to collect data (i.e., police records, victim statements, psychological assessments, etc). Results indicate that the age of the victim and the presence of deviant sexual fantasies were found to be related to the use of physical force during sexual offences against children. Age of onset, childhood sexual victimization, and negative affects were found to be associated with the use of physical force during sexual offenses perpetrated against an adolescent or adult female. To better understand the development of sexual offending, future studies should examine other criminal career activity parameters