Mechanisms of Community Prosecution: Evidence from Cook County

Abstract: A new strategy of criminal prosecution, called “community prosecution,” emerged in the past two decades. The strategy breaks with the traditional approach to prosecution in which a prosecutor works in an office adjacent to a criminal court, processes a large volume of cases, and measures success with conviction rates and sentence lengths. In community prosecution, a prosecutor works directly in a neighborhood, develops relationships with local groups, aligns enforcement priorities with residents’ public safety concerns, and seeks solutions to prevent crime ex ante. Recently, Miles (2014) studied two episodes in which Cook County, Illinois, applied the community prosecution strategy, and his differences-in-differences estimates reduced certain categories of crime, such as aggravated assault, but had no effect on other categories, such as larceny. This paper examines the mechanisms through which the crime declines occur by considering whether community prosecution also affected clearance rates. If clearance rates increased (while crime fell) in response to the introduction of community prosecution, it would indicate that a causal mechanism through which community prosecution reduces crime is through increased resident cooperation with law enforcement authorities. The paper is the first to study which institutional features of the multi-faceted community prosecution strategy cause the drops in crime.