In the mid-1990s New York City inaugurated its era of mass misdemeanors by pioneering policing tactics featuring intensive enforcement against low-level offenses as part of its quality-of-life and urban crime control strategy. These tactics have since spread across the country and around the globe. But the New York City experiment embarrasses our traditional understanding of how an expansion of criminal enforcement should work: as misdemeanor arrests climbed dramatically as part of an intentional law enforcement strategy, the rate of criminal conviction fell sharply. Using extensive, original data from a multiyear study, this Article exposes an underappreciated model of criminal administration in New York City\u27s processing of mass misdem...