Peter Moskos investigates one of urban America's most remarkable crime declines: how New York City cut murders in half between 1993 and 1996. Drawing on interviews with the officers, commanders, and officials who were there, Moskos reconstructs the tactical and organizational changes that drove the reduction. The book examines CompStat, the data-driven management system that held commanders accountable for crime in their precincts; the focus on quality-of-life offenses that identified offenders before they committed violence; and the street-level work of officers who learned to read their territories. Moskos is clear-eyed about costs: aggressive enforcement produced complaints about civil liberties, tensions with minority communities, and cases of excess. But he argues that understanding how crime fell is essential for addressing current concerns about violence. The book speaks to contemporary debates about policing, offering historical evidence about what worked while acknowledging the difficult tradeoffs involved in public safety.