Impacts of BWCs on Officer Activity: Directory of Outcomes

Impacts of BWCs on Officer Activity: Directory of Outcomes


BWC TTA (2020)


Jessica Huff, Dr. Janne E. Gaub, Dr. Michael D. White, and Dr. Aili Malm

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, officer activity). 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 officer activity 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 Officer Activities BWC Outcome Directory (2/14/20)

The Officer Activity Directory provides information on 14 published studies or reports that examine the impact of BWCs on the prevalence of arrests, citations, and self-initiated activities. Twelve studies examine arrest, four examine citations, and eight examine self-initiated activities. It is unknown whether a change in any of the activity measures is positive or negative. Is an increase in arrests positive? Is a decrease in arrests positive? Neither is clear. Same with self-initiated activity. A decrease could indicate a form of de-policing as officers disengage. Or an increase could be received negatively by the community. The local context of the findings matters greatly. A few notable findings emerge: 

  1. Eight of the 14 studies are randomized controlled trials (RCTs), displayed as Level 5 on the Maryland Scientific Methods Scale (MSMS). Two studies are Level 3 and just one is a Level 2. This finding highlights the robust methodological rigor of the rapidly growing body of research on BWCs.
  2. Six of the 12 studies showed no impact on arrest activity. Four studies report substantial or statistically significant increases in arrests, and two studies report the opposite (substantial or statistically significant decreases). The evidence examining the impact of BWCs on arrest activity is mixed.
  3. The findings related to citations are more definitive. Three of 4 studies reported substantial or statistically significant increases in citations following deployment of BWCs. One study reported a statistically significant decrease in citations. The evidence suggests that BWCs may lead to an increase in citations.
  4. Five of the eight studies found BWCs had no impact on self-initiated activity. Two studies showed an increase, and one showed a decrease. The evidence suggests that BWCs typically do not affect officer self-initiated activity.