Administrative agencies seeking to impose sanctions for regulatory violations can handle matters internally or through civil or criminal courts. Organizational culture, legal constraints, and political and private actors may influence governance and hence choice of enforcement venue. An enforcement behavior model is constructed and tested empirically using a 1990-1997 sample of Environmental Protection Agency (EPA) air, water, and hazardous waste penalty cases involving individuals. While EPA's enforcement arm embraces the mission of its regulatory arm--minimizing environmental harm--in part, it also has attributes of a police and prosecution force--specifically deterring (and maximizing social welfare) or incapacitating individual violators. Nevertheless, EPA may fail to minimize violations of and generally deter non-culpable individuals who are affiliated with large firms. (Contains 4 footnotes, 7 tables, and 1 figure.)