This chapter “Have Changes in Policing Reduced Violent Crime? An Assessment of the Evidence” examines research evidence on the contributions of American police to the crime drop of the 1990s in the United States. The chapter considers three generic changes in policing thought by some to have influenced the crime drop, including community policing, zero-tolerance policing, and increasing the number of police officers. Next, the chapter considers four focused policing strategies, including Compstat, gun interdiction patrols, retail drug enforcement, and problem-oriented policing. The findings suggest that police were responsible for some portion of the crime drop of the 1990s, but the evidence does not support some of the most popular claims for the effects of police on crime. Overall, the research suggests that generic strategies like community policing and increasing the number of police officers are less effective than more focused policing strategies that target problem people and places.