In business processes, modeling is usually a collaborative activity. In it stakeholders analyze or design business processes. One of the challenges is that group members have diverse backgrounds and conflicting interests which make it difficult to arrive at a model that represents a consensus. It is therefore important to study the way in which modeling teams are organized to overcome these problems. To approach this issue we investigated the modeling behavior of such groups with the help of a tool that supports collaborative modeling while at the same time allowing for the effective collection of data on modeling activities. Besides confirming known roles we also discovered a new one, editor, that only emerges in tool-supported sessions and that functions as a mediator between modeling experts and domain experts.