Impacts of BWCs on Use of Force: Directory of Outcomes

Impacts of BWCs on Use of Force: Directory of Outcomes




Dr. Michael D. White, Dr. Janne E. Gaub, and Kathleen E. Padilla


The research base on the impact of police body-worn cameras (BWCs) has grown rapidly, and over time, the results have become increasingly mixed. This development poses two problems: 

  1. It is difficult to keep track of the quickly growing evidence base 
  2. It is difficult to make sense of the sometimes competing findings across studies 

Moreover, studies can vary widely in terms of their methodological rigor. We have developed the Body-Worn Camera Outcome Directories to address these two problems. The Directories provide a comprehensive, up-to-date overview of the existing research by outcome (use of force, citizen complaints). Importantly, each study’s entry has been approved by the primary researcher to ensure accuracy (when the primary researcher could not be reached, an independent reviewer was tasked with peer-reviewing the interpretation of the study’s findings).  Each directory is presented in two formats: A summary version and a detailed version. Both versions contain, for each study, the agency being evaluated, the agency’s state or country, the researchers conducting the study (with a link to the study), the year in which the study was published, an assessment of the study’s methodological rigor using the Maryland Scientific Methods Scale, and summaries of the study’s findings using visual indicators (green down-arrow, red up-arrow, or yellow dot). The detailed version of the directories also includes the percent change for between- and within-group comparisons and study sample size. More detailed instructions for interpreting the directories are included in each document. 

Currently, directories for use of force are available below, though additional outcomes are forthcoming.  If you have any questions, please contact Dr. Michael White (, Dr. Janne Gaub (, or the BWC TTA Team (

Summary of the Use of Force BWC Outcome Directory (3/25/19)

The Use of Force Directory provides information on 19 published studies or reports that examine the impact of BWCs on the prevalence of use of force. Two notable findings emerge:

  1. Eleven of the 19 studies are randomized controlled trials (RCTs), displayed as Level 5 on the Maryland Scientific Methods Scale (MSMS). Only two studies are below Level 3. This finding highlights the robust methodological rigor of the rapidly growing body of research on BWCs.
  2. Eleven of the 19 studies report substantial or statistically significant reductions in use of force, following deployment of BWCs.

Taken together, the current body of research suggests that police BWCs can lead to reductions in use of force by police.