Resolution Economics provided consulting services to a large city police department in connection with a Department of Justice investigation regarding allegations of racial profiling. We analyzed departmental information related to over 130,000 traffic stops, pedestrian stops, and other types of police contacts that occurred during the study period. We effectively cross-referenced traffic stops data with other information sources including human resources data, precinct level paper records, and the officer discipline system to test various hypotheses. We were able to show that much of the surface disparities were directly correlated with fairly obvious differences in the areas within which police work was conducted. That is, differences in the frequency of stops by race were closely related to where the stops were being made. Within geographic areas, rates of stop were equal by race – but more stops were made in some areas than others. The rates of stops overall by areas were found to relate closely to levels of crime by area. The department involved settled the initial claim.