• policing;
  • race;
  • traffic stops;
  • searches;
  • racial stratification

 Research on race effects in police traffic stops is theoretically underdeveloped. In this study, we derive propositions from Donald Black's theory of law to explain the interaction effects of officer and driver race on searches in traffic stops in St. Louis, Missouri. Our citywide results and those for stops in predominantly White communities are generally consistent with the theory: Searches are more likely in stops of Black drivers than in those of White drivers, especially by White officers, controlling for other characteristics of the officer, driver, and stop. In predominantly Black communities, however, stops of White drivers by White officers are most likely to result in a search. We interpret both sets of results as manifestations of racial profiling in segregated communities and suggest that Black's theory of law remains a promising theoretical framework for future research on the continuing significance of race-based policing in the United States.