Objective: Violence perpetrated by groups has been proposed to result from processes that include deindividuation, instrumental responses to victim resistance, and leader-follower dynamics. Here we compare the explanatory merit of these accounts by analyzing the sequential patterns of behaviors that occurred in 71 accounts of multiple perpetrator rape by 189 suspects against lone females. Method: Victim accounts of the offenses made to the police were coded for leader, follower, and victim actions using the interpersonal circumplex quadrants, and the offenses were rated as involving high or low nonsexual aggression. Results: Analysis of the temporal proximities among victim and suspect behaviors found that (a) in contrast to deindividuation, hostility decreased rather than increased with group size, (b) victim behavior had no significant effect on perpetrator violence, and (c) leader behavior had a significant effect on group violence. Conclusions: Compared with low aggression offenses, high aggression offenses were characterized by the leaders' hostile behaviors reinforcing the hostile behavior of followers, as well as there being some mutual reinforcement from follower(s) to leader. This has implications for theories of (sexual) violence perpetrated by multiple individuals, as well as for clinical work with such offenders. For example, the influence of peers in these offenses has implications for the planning of interventions with such offenders and the sorts of intervention that are likely to be successful.