Community and problem-oriented policing have shaped the debate over the role of the American police for three decades. In the 1990s, the federal government provided billions of dollars via the COPS program to promote police reform. Dining this time, community and problem-solving practices became more common. Research focusing specifically on whether COPS grants directly resulted in reductions in crime remains mixed. Two archetypes of community policing can be identified, each rooted in a different neighborhood theory of crime: broken windows theory and social disorganization theory. Problem-oriented policing draws on theories of criminal opportunity, such as routine activity and rational choice theory, to direct interventions aimed at altering environmental conditions to reduce crime and disorder. The weight of the empirical evidence is that community and problem-oriented policing can reduce crime and disorder. Many important questions require systematic investigation.