Both in the U.S. and internationally, policing has undergone fundamental changes over the past decades. Changes in the policing workplace and in the mission of policing have led to new theories and models of policing, changes in the relationships between citizens and police, and a rethinking of the role of policing in the modern world. Yet police remain the first line response to problems of disorder and crime, and gatekeepers to the criminal justice system. This seminar will examine theories of policing, exploring assumptions about the police function, policy implications for criminal law, and empirical evidence supporting or refuting the effectiveness of particular strategies and approaches. Professional law enforcement, the organizational strategy that has dominated policing in modern times, will be contrasted with community and problem-oriented approaches to the police function. We will discuss the implications of the contemporary policing workplace, including both the diversification of the police workforce and new methods of police management and supervision. Specialized topics will include use of force, selective enforcement and profiling, police discretion, the rise of private policing, civilian review, order maintenance, litigation and consent decrees, and the intersection of policing and national security.