Cincinnati Police Department Traffic Stops

In 2002, the Cincinnati Police Department (CPD), through a collaborative agreement, joined with other organizations to improve police-community relations. As a part of this agreement, Cincinnati asked RAND to evaluate progress toward achieving the agreement's goals. This monograph focuses on three assessments that evaluate whether data on traffic stops exhibit evidence of racial profiling: (1) an assessment of whether there is a department-wide pattern of bias against black drivers in the decision to stop a vehicle, (2) an assessment of the fraction of CPD officers who disproportionately stop black drivers compared to other officers patrolling the same neighborhoods at the same time, and (3) an assessment of racial biases in post-stop outcomes, including stop duration, citation rates, and search rates. RAND has developed a framework for conducting each of these assessments, and this monograph describes the associated methodology in detail. The framework removes the effect of other plausible explanations for racial differences, particularly adjustments for when, where, and why stops occur, to isolate race's effect from that of other factors on the decision to stop, cite, and search vehicles. In addition to providing an analysis of Cincinnati's traffic stops for 2008, the framework offers direction for Cincinnati and other communities concerned about racial profiling to assess their traffic-stop data.