Do police body cameras reduce the number of fatal incidents?
Executive summary
Evidence is mixed: several randomized and quasi‑experimental studies find body‑worn cameras (BWCs) reduce overall use‑of‑force and complaints—one Crime Lab paper reports a near 10% drop in use‑of‑force and ~17% fewer complaints [1] [2] [3]—but systematic reviews and federal overviews conclude effects on fatal encounters are inconsistent or not statistically significant [4] [5]. Newer research shows any reduction in police‑involved homicides is uneven, concentrated where prior fatality rates were high and where strict activation policies exist [6].
1. What the strongest experiments say: modest, measurable reductions in use‑of‑force
Randomized trials and large evaluations have documented reductions in use‑of‑force and civilian complaints after BWCs were introduced. The University of Chicago Crime Lab and related trials reported roughly a 10% reduction in police use of force and declines in complaints and investigations in the studied departments [1] [3] [2]. Earlier high‑profile local experiments—like Rialto—found steep declines in reported use‑of‑force when cameras were used [7] [8].
2. But do BWCs cut fatal incidents? The literature is inconclusive
Reviews and federal analyses emphasize that effects on fatal encounters are not consistent. A federal synthesis of 70 studies found “no consistent or statistically significant effects” of BWCs on fatal encounters with civilians [4]. Similarly, civil‑liberties and advocacy summaries cite mixed results and warn the technology has not reliably decreased police violence across the board [5] [9].
3. Newer academic work: reductions exist, but they are heterogeneous
A 2025 working paper finds reductions in police‑involved homicides occur primarily in places that already had higher rates of such incidents and in agencies that enforce stricter activation rules for cameras; agencies in low‑incident areas or with weak activation policies see no measurable change [6]. This points to policy design and baseline conditions as the drivers of any fatality‑related benefits, not cameras alone [6].
4. Activation rules, policy design and organizational context matter
Multiple sources show camera effectiveness depends on how they are used. When officers control activation and footage, the deterrent effect weakens or disappears; some studies report increases in use‑of‑force when activation is discretionary [8]. Conversely, strict activation protocols and technologies like “smart holsters” that auto‑activate devices are highlighted as mechanisms that could improve outcomes [10] [6].
5. Footage availability and institutional incentives shape outcomes
Body cameras do not automatically generate transparency. Investigations show footage is often withheld, redacted, or subject to selective release; in documented cases footage was available but not released in a large share of deadly incidents [9]. Advocacy groups warn that camera control by police and limits on public access can produce an illusion of accountability while insulating misconduct [5] [9].
6. Why fatalities are hard to study and why results vary
Fatal police encounters are rare relative to other uses of force, making robust statistical detection difficult in many studies; researchers use staggered roll‑outs and quasi‑experimental designs to gain power, but results still vary by jurisdiction and policy context [11] [12]. Systematic reviews aggregate many small, different studies and therefore often conclude effects on rare outcomes like fatalities are inconsistent [4] [12].
7. Competing interpretations and implicit agendas to watch for
Pro‑BWC research and policy briefs stress cost‑effectiveness and reductions in complaints and nonfatal use of force [3] [1]. Civil‑liberties organizations and some reviews emphasize the limits of cameras to address structural problems—arguing they can be used to defend officers, fail to capture critical angles, or be withheld [5] [9]. Both sides often promote solutions aligned with their aims: technocratic fixes and cost‑benefit claims versus calls for broader accountability reforms.
8. Bottom line for policymakers and the public
Available studies show BWCs can reduce complaints and some uses of force and may reduce fatalities in targeted contexts—especially where activation is mandatory and prior fatality rates were high—but they are not a universal solution to police killings [1] [6] [4]. Effectiveness depends on deployment rules, agency transparency, and complementary reforms; absent strict activation and release policies, cameras alone do not reliably prevent fatal incidents [8] [9].
Limitations: This analysis relies only on the supplied reporting and studies; available sources do not mention long‑term behavioral adaptation after many years of use, nor do they provide a consensus causal estimate applicable to all departments (not found in current reporting).