In January 2015, the Boston Police Department (BPD) committed to implement a pilot body worn camera (BWC) program for its officers. This pilot was intended to help answer policy questions about how the system would operate if and when fully implemented across the department’s 2,100 officers and to address concerns of officers and community members on the use of the technology. Boston Mayor Martin Walsh and Boston Police Commissioner William Evans committed to a rigorous evaluation of this pilot program. The BPD implemented its BWC pilot program in September 2016. This pilot involved the random allocation of 100 BWCs to officers who wore these cameras for a twelve month intervention period. The impact evaluation uses a rigorous randomized controlled trial (RCT) design to evaluate the impact of BWCs on police-citizen interactions, police proactivity, police lawfulness, and police-community relations.1 RCTs are generally considered the “gold standard” in program evaluation as these designs allow researchers to assume that the only systematic difference between the control and treatment groups is the presence of the intervention; this permits a clear assessment of program impacts on outcome measures.

This preliminary impact evaluation report summarizes the randomization of officers to treatment and control groups, assesses the balance between experimental groups, examines attrition in the treatment group, and estimates the statistical power of the experimental design. The report then presents preliminary evaluation findings for the impact of the BWC technology on citizen complaints against officers and officer use of force incident reports.

To read the full report, click here.