The 24 offender groups studied committed sex offenses in 47 different situations. Sixty-three percent of the offender groups committed one or more group sex offenses in a single victimization. The group sex offenses generally involved rapes. Some victims were repeatedly raped by several different offenders while the others in the group watched the rape. Perpetrators generally had below-average intelligence and were between 12 and 18 years old. They were average in terms of impulsiveness, neuroticism, extraversion, and sensation-seeking. The average size of the offending groups was four. In some cases the offenders had a premeditated consensus to rape a victim. In other cases, the sexual assault was opportunistic and without planning. In one-third of the group attacks, a leader orchestrated the offense. The group often regarded the victimization as entertainment. In many cases the victim was threatened, even after the offense was completed. There were two types of initial contact with the victim. One type involved normal contact and conversation prior to forcibly taking the victim to a different location where she was assaulted. A second type of interaction with the victim involved an immediate groping and bullying of the victim. The authors concluded that juvenile group sex offenders had profiles that resembled nonsexual violent offenders rather than sex offenders who act alone. Offenses were reconstructed from court files and information obtained from personality evaluations. The sample consisted of 42 offenders who had committed sex offenses within 24 different offender groups. 31 references