The police shooting of an unarmed young black man in the St. Louis suburb of Ferguson, Missouri, in August 2014 sparked riots and the beginning of a national conversation on race and policing. Much of the ensuing discussion has focused on the persistence of racial disparities and the extraordinarily high rate at which American police kill civilians (an average of roughly three per day). Malcolm Sparrow, who teaches at Harvard’s Kennedy School and is a former British police detective, argues that other factors in the development of police theory and practice over the last twenty-five years have also played a major role in contributing to these tragedies and to a great many other cases involving excessive police force and community alienation. Sparrow shows how the core ideas of community and problem-solving policing have failed to thrive. In many police departments these foundational ideas have been reduced to mere rhetoric. The result is heavy reliance on narrow quantitative metrics, where police define how well they are doing by tallying up traffic tickets issued (Ferguson), or arrests made for petty crimes (in New York). (Photo: [Tobin B./Flickr](https://www.flickr.com/photos/tobanblack/3762525969 ""))