The study examined the effects of body-worn cameras (BWCs) on civilian complaints against police using a non-representative national sample of police organizations.
The empirical approach employed a staggered difference in differences design (DiD) that exploited the variation in the timing of adoption of BWCs by police agencies from 2007 to 2016. The study considered two scenarios: (1) a model without any explanatory variables; and (2) a model with explanatory variables. Furthermore, in each model the author two different comparison groups: (1) agencies that never adopted this technology and (2) agencies that adopted BWCs at a later time.
The model without explanatory variables suggest strong and statistically significant reductions in complaints. The simple average estimates show reductions in civilian complaints between 13% and 14%, depending on the model. This is the equivalent of an average reduction of about 30 civilian complaints per capita. The dynamic effects suggested that the length of exposure to BWCs matters in reducing civilian complaints, showing a significant reduction of 47% in civilian complaints. The models with explanatory variables also show slightly lower declines in civilian complaints.
The surge in the adoption of BWCs by police agencies sparked a parallel surge of studies examining their effectiveness on various outcomes. Most research to date has use experimental designs on a single police agency or a small group of agencies. Few studies have employed a large sample of agencies or periods longer than six to 12 months. Evidence on the effects of BWCs on a range of outcomes from larger multi-agency studies and longer periods of analysis will support the already robust specialized literature and inform policymakers about the effectiveness of this technology over time.
