Mobility patterns of first responders (FRs) have distinct properties from other well-studied networks, such as vehicular and campus networks. FRs are mission-oriented. They are organized, cooperative and responsive to emergency situations. In this paper, we propose a novel mobility model, CORPS, which captures both environmental and operational determinants for FR's movement. CORPS is an event-driven mobility model with event-oriented characterization. We also integrate CORPS mobility model in CORPS MobiGen architecture, an automated and easy-to-use mobility pattern generation tool. Experiments show that CORPS reflects operational logistics of FRs and yields distinct topology characteristics and routing protocol performance.