The Impact of Body-Worn Cameras: Perceptions and Reality

Camera Lens with Police Lights Shining


November 16, 2017

As the move toward body-worn cameras (BWCs) increases, a growing body of research tells us a lot about the impact and consequences of the technology. We examine several popular conceptions (or misconceptions) about BWCs in light of what research evidence reveals.

Police Officers Don't Like BWCs - FALSE

The available research tells us this is false. While it is popular to think that the main purpose of BWCs is to expose police misconduct and correct it, and thus that police do not like BWCs, the opposite appears to be the case. Police leadership organizations, including the International Association of Chiefs of Police (IACP), publicly support BWCs. The rapid adoption of cameras is also evidence that law enforcement embraces this technology. One source estimates that one-third of the approximately 18,000 police departments in the United States are using or plan to use BWCs, and the number is growing.[i]

Perhaps the most compelling evidence of law enforcement’s support for BWCs comes from police officers themselves. Researchers have examined officer perceptions of the technology in a half-dozen departments across the country and results show strong support before officers are assigned BWCs. The support becomes even stronger post-deployment.[ii]

Police officers have concerns about the technology, most notably how policy dictates the nature and frequency of supervisor review. In our experience, several police bargaining units have argued that BWCs represent a change in working conditions and use their introduction as a lever in bargaining negotiations. Research also demonstrates that line officers’ concerns about the technology can be alleviated by addressing this issue directly in the policy (for example, restricting supervisor review of BWC footage to instances involving complaints, use of force or random quality checks), and by implementing a BWC planning and implementation process that is inclusive of line officers and collective bargaining representatives, gives them voice, and allows them to express their concerns.

Residents Approve Police Adoption of BWCs - TRUE

The available research tells us this is true. BWCs have been publicly embraced by a number of resident advocacy and human rights groups, including the American Civil Liberties Union[iii]and the National Association for the Advancement of Colored People, citing their value in promoting transparency and public trust. These stakeholders have their own ideas about core issues surrounding resident privacy, officer accountability and public access to video, but they support the technology in principle. Also, survey research with general population samples shows that residents, as a whole, are strongly supportive of police BWCs[iv]. In addition, research examining the attitudes of people who are most affected by the technology, the residents whose encounters with police are recorded, shows that this important subgroup strongly supports the technology.[v]

BWCs Can Lead to Reductions in Police Use of Force and Resident Complaints – TRUE with some caveats

Research supports this claim, with some important caveats. The majority of BWC studies report significant reductions in these two important outcomes following deployment of BWCs. An evaluation of BWCs in the Rialto, California, Police Department documented a nearly 90 percent drop in resident complaints against police, and a 60 percent decline in use of force by officers[vi]. Similar positive results have emerged from studies in Mesa, Arizona;[vii] Orlando, Florida;[viii] and Las Vegas, Nevada.[ix]

However, the potential for significant change in use of force and resident complaints can be short-circuited by implementation failure. If officers do not consistently activate the BWC and departments do not ensure that their officers are complying with policy on activation, the benefits of BWCs will not be realized, and early evidence suggests things could actually get worse. Barak Ariel and colleagues examined data from nearly a dozen different police departments in the United Kingdom and the United States, and they tied patterns in use of force to officer decisions on BWC activation.[x] When officers followed policy—they activated the BWC at the start of resident encounters and advised residents of the BWC—use of force declined by 37 percent. When officers did not follow policy on activation and on notifying residents about the presence of a camera, use of force increased by 71 percent. If BWCs are used as intended, the technology can lead to reductions in resident complaints and use of force.

BWCs Generate Valuable Evidence - TRUE

Research supports this notion as well. Several studies have documented BWCs’ evidentiary value. A Scottish study found that BWC cases were 70 to 80 percent more likely to result in a guilty plea, compared to other court cases.[xi]

Another U.K. study reported that BWCs led to quicker resolution of cases, less officer time devoted to paperwork, and more time spent on patrol.[xii] Weston Morrow and colleagues reported that BWCs led to enhanced criminal justice outcomes for domestic violence cases in Phoenix, Arizona;[xiii] and a study in Essex, England, reported similar findings.[xiv] A recent BWC evaluation in Las Vegas, Nevada[xv] revealed that BWC footage dramatically increased officer exonerations in complaints filed against them and significantly reduced the time and expenses required to resolve complaints against officers.

BWCs Will Always Capture What Happens During a Police-Resident Encounter - FALSE

The available evidence tells us this is false. BWCs have numerous limitations that affect the likelihood that they will capture a complete visual and audio record of what has transpired. The first set of limitations involves the human component. An officer may forget or choose not to activate the BWC. Critical incidents involving the police can begin in an instant and are extremely fluid. As a consequence, the officer may activate the camera but not until after his or her safety, or the safety of a resident, is no longer threatened. Moreover, the camera may be activated but may not actually provide evidence about what happened. The view from the camera may be obstructed by the officer’s “shooting platform” (that is, a shooting stance with outstretched arms often will block a chest-mounted BWC).

Alternatively, the officer may see something critical through his or her peripheral vision, or the officer may turn his or her head without turning the rest of his or her body so the camera is facing forward while the officer is looking to the left or the right. During foot pursuits and struggles with residents, the video from a BWC can become unwatchable, or the device can fall off the officer, though audio can still provide critical evidence of what is transpiring.

In short, the added advantage of BWCs over dashboard cameras is that the BWC goes where the officer goes; however, this can also be a limitation. There is no film crew on the scene to ensure a bird’s-eye view with perfect lighting.

For more information visit:

Michael D. White, PhD, School of Criminology and Criminal Justice, Arizona State University (ASU); associate director, ASU’s Center for Violence Prevention and Community Safety; and co-director of training and technical assistance, U.S. Department of Justice’s Body-Worn Camera Policy and Implementation Program

James R. “Chip” Coldren Jr., PhD, managing director for justice programs, CNA’s Institute for Public Research, Arlington, Virginia; directs CNA’s projects pertaining to BWC technical assistance; and is a lead investigator on CNA’s randomized experiment with BWCs at the Las Vegas Metropolitan Police Department


[i] Katie Delong and CNN Wire Service, “One-Third of United States Police Departments Using Body Cameras: They’re Expensive, so Are They Worth It?”, Milwaukee, March 2, 2015,

[ii] Janne E. Gaub et al., “Officer Perceptions of Police Body-Worn Cameras Before and After Deployment: A Study of Three Departments,” Police Quarterly 19, no. 3 (2016): 275-302; and Wesley G. Jennings, Lorie A. Fridell, and Matthew D. Lynch, “Cops and Cameras: Officer Perceptions of the Use of Body-Worn Cameras in Law Enforcement, Journal of Criminal Justice 42 (2014): 549–556.

[iii] Jay Stanley, “Police Body-Mounted Cameras: With Right Policies in Place, a Win for All: Version 2.0,” American Civil Liberties Union, last updated March 2015,

[iv] William H. Sousa, Terance D. Miethe, and Mari Sakiyama, Research in Brief: Body Worn Cameras on Police: Results from a National Survey of Public Attitudes (Las Vegas: University of Nevada–Las Vegas, Center for Crime and Justice Policy, 2015).

[v] Michael D. White, Natalie Todak, and Janne E. Gaub, “Assessing Citizen Perceptions of Body-Worn Cameras After Encounters with Police,” under review at Policing: An International Journal of Police Strategies and Management, 2016; Michael D. White, Janne E. Gaub, and Natalie Todak, “Assessing the Impact and Consequences of Police Officer Body-Worn Cameras,” paper presented at the 2016 American Society of Criminology meeting, New Orleans, 2016; and Pew Research Foundation, “Behind the Badge,” Social and Demographic Trends (Washington, DC: Pew Research Foundation, January 11, 2017).

[vi] Barak Ariel, William A. Farrar, and Alex Sutherland, “The Effect of Police Body-Worn Cameras on Use of Force and Citizens’ Complaints Against the Police: A Randomized Controlled Trial,” Journal of Quantitative Criminology 31, no. 3 (2015): 1–27.

[vii] On-Officer Body Camera System: Program Evaluation and Recommendations (Mesa, AZ: Mesa Police Department, 2013).

[viii] Wesley G. Jennings, Matthew D. Lynch, and Lorie A. Fridell, “Evaluating the Impact of Police Officer Body-Worn Cameras (BWCs) on Response-to-Resistance and Serious External Complaints: Evidence from the Orlando Police Department (OPD) Experience Using a Randomized Controlled Experiment,” Journal of Criminal Justice 43, no. 6 (2015): 480–486.

[ix] Anthony Braga, James Coldren, William Sousa, Denise Rodriguez, and Omer Alper, The Benefits of Body-Worn Cameras: New Findings from a Randomized Controlled Trial at the Las Vegas Metropolitan Police Department (under review), (Washington, DC: National Institute of Justice, 2017).

[x] Barak Ariel et al., “Report: Increases in Police Use of Force in the Presence of Body-Worn Cameras Are Driven by Officer Discretion: A Protocol-Based Subgroup Analysis of 10 Randomized Experiments,” Journal of Experimental Criminology (2016), DOI: 10.1007/s11292-016-9261-3.

[xi] Body Worn Video Projects in Paisley and Aberdeen: Self Evaluation (Glasgow, UK: ODS Consulting, 2011).

[xii] Martin Goodall, Guidance for the Police Use of Body-Worn Video Devices, (London:  Home Office, 2007),

[xiii] Weston J. Morrow, Charles M. Katz, and David E. Choate, “Assessing the Impact of Police Body-Worn Cameras on Arresting, Prosecuting, and Convicting Suspects of Intimate Partner Violence,” Police Quarterly 19, no. 3 (2016): 303–325.

[xiv] Catherine Owens, David Mann, and Rory McKenna, The Essex Body Worn Video Trial: The Impact of Body Worn Video on Criminal Justice Outcomes of Domestic Abuse Incidents (Essex, UK: College of Policing, 2014).

[xv] Anthony Braga, James Coldren, William Sousa, Denise Rodriguez, and Omer Alper, The Benefits of Body-Worn Cameras: New Findings from a Randomized Controlled Trial at the Las Vegas Metropolitan Police Department (under review), (Washington, DC: National Institute of Justice, 2017).