Police Ethics, Fourth Edition, provides an analysis of corruption in law enforcement organizations. The authors argue that the noble cause—a commitment to “doing something about bad people”—is a central “ends-based” police ethic. This fundamental principle of police ethics can paradoxically open the way to community polarization and increased violence, however, when officers violate the law on behalf of personally held moral values. It provides students of policing with a realistic understanding of the kinds of problems they will confront in the practice of police work. This timely new edition offers police administrators direction for developing agency-wide corruption prevention strategies, and a re-written chapter further expands our level of understanding of corruption by covering the Model of Circumstantial Corruptibility in detail.