"Police body cameras do not reduce use-of-force incidents."
Evidence3
A Campbell review of 30 high-quality body-camera studies found no clear, consistent reduction in police use of force.
Campbell Collaboration published this evidence review, and the authors are Cynthia Lum and Christopher S. Koper, criminology researchers associated with George Mason University.
The review combined high-quality evaluations of police body cameras, including randomized controlled trials and quasi-experimental studies.
The search window covered studies available through September 2019, and the final pool included 30 evaluations with 116 measured effects across outcomes.
The outcomes included use of force, citizen complaints, arrests, officer activity, and related police-citizen interaction measures.
The overall pattern was mixed, and the review reports substantial uncertainty about force reduction, meaning the effect was not consistently strong across settings.
Campbell Collaboration published this evidence review, and the authors are Cynthia Lum and Christopher S. Koper, criminology researchers associated with George Mason University.
The review combined high-quality evaluations of police body cameras, including...
A randomized Washington, DC trial with 2,224 officers found no statistically significant change in force reports or civilian complaints.
This evidence comes from an Office of Justice Programs publication describing a citywide Metropolitan Police Department trial in Washington, DC.
The study used a randomized controlled design, which is a strong method for testing whether cameras themselves caused differences in outcomes.
The trial included 2,224 officers and measured documented use-of-force incidents and civilian complaints as primary outcomes.
The publication date is October 2017, but this source summary does not provide one exact inspection-period date range in the page text.
The reported result is that average effects were not statistically significant for the main outcomes, so cameras alone did not produce a clear system-wide drop in those measures.
This evidence comes from an Office of Justice Programs publication describing a citywide Metropolitan Police Department trial in Washington, DC.
The study used a randomized controlled design, which is a strong method for testing whether cameras themselves...
NIJ summarizes that a broad review of 70 body-camera studies found no consistent, statistically significant overall effect, including on force outcomes.
The National Institute of Justice, the U.S. Department of Justice research agency, publishes this summary page.
It synthesizes results across many body-camera evaluations and cites a comprehensive review covering 70 studies.
The evidence base includes multiple methodologies, and NIJ also references CrimeSolutions ratings that classify several programs as showing no effects on core outcomes in some settings.
Outcomes discussed include use of force, citizen complaints, arrests, and officer safety-related measures.
The overall pattern is mixed: some local programs report improvements, but the cross-study signal is not consistently statistically significant for force reduction across the full literature.
The National Institute of Justice, the U.S. Department of Justice research agency, publishes this summary page.
It synthesizes results across many body-camera evaluations and cites a comprehensive review covering 70 studies.
The evidence base includes...