Effect of Body-Worn Cameras and Consent Decrees on Racial Disparities in Policing

What the evidence says

The evidence set for this topic does not contain a single measured effect of body-worn cameras (BWCs) or consent decrees on racial or ethnic disparities in policing outcomes. What it contains instead is a repeated, explicit statement from two related systematic reviews — a 2019 review protocol and its 2020 completed review, both by Cynthia Lum and colleagues in Campbell Systematic Reviews — that this outcome has not been studied. The 2020 review, which screened studies down to 30 eligible for its meta-analysis, states directly that the impact of BWCs on "racial and ethnic disparities in policing outcomes" was among the outcomes needing more research and was not addressed by the studies it reviewed. No claim in this set reports a direction, magnitude, or statistical result for disparity as an outcome — there is no number to report because none was measured.

The claims do establish why this gap is notable: agencies adopted BWCs in part because of concerns about racial and ethnic disparities. Adoption was "propelled by highly publicized and filmed events involving (often) White police officers killing (often) unarmed Black individuals," and reducing disparity was one of the "high expectations" agencies held for BWCs at the time of adoption — alongside increasing accountability, reducing use of force, and improving community relationships. The claims are explicit that agencies adopted the technology "without clear knowledge about whether the technology could deliver" on that expectation. This is a claim about the motivation for a policy, not about its effect, and it is treated that way here.

Consent decrees do not appear in any claim in this evidence set. No source here measures, or even mentions, an effect of consent decrees on racial disparities in policing. That is a complete absence, not a null or contested finding.

Where the evidence splits

No contradictions in the current sources.

Thresholds and dose-response

No threshold established in the current sources.

Open empirical questions

• Whether BWC deployment changes rates of stops, use of force, arrests, or other policing outcomes by race or ethnicity — unmeasured in the sources reviewed here.
• Whether consent decrees have any measurable effect on racial disparities in policing outcomes — absent entirely from this evidence set.
• Why 30 eligible studies reviewed by 2020 still left this outcome untested, and whether later studies (post-2020) have closed the gap.