The effects of body-worn cameras on police-citizen encounters and police activity: evaluation of a pilot implementation in Philadelphia, PA

Objectives Examine changes in officer behavior, when wearing body-worn cameras, as revealed by pedestrian stops, vehicle stops, arrests, use of force, and citizen complaints during a pilot implementation in a racially diverse jurisdiction in the Northeast region of the USA. Methods A quasi-experimental approach was used to examine the initial implementation of body-worn cameras (BWCs) in one district. This provided the opportunity for a natural experiment comparing officers in the district that deployed cameras with officers in three similar districts where no BWCs were deployed. Propensity score matching (PSM) was used to match BWC officers with non-BWC officers. Results BWC officers had about 38.3% fewer use of force incidents than non-BWC officers with similar numbers of use of force incidents in the previous year. On average, BWC officers made 46.4% fewer pedestrian stops and 39.2% fewer arrests than non-BWC officers. Vehicle stops and citizen complaints had nonsignificant declines for BWC officers. Conclusions The reductions in proactive policing by officers are consistent with a deterrence-based view that officers respond to the increased scrutiny by curtailing interactions with citizens, which in turn, limits the potential for conflict and for police supervisors to identify behavior worthy of disciplinary action. The lack of a significant reduction in citizen complaints supports the view that the effect of BWCs on negative officer behavior is contingent upon other factors in the settings in which cameras are deployed. Future research should examine the impacts of cameras on the narrowing of police discretion because of the important implications for police-community relations.