Since mid-2014, a persistent spate of police killings of residents has produced public outrage, civil disorder, and strong antipolice sentiment, especially among minority residents. In response to this crisis, in December 2014, President Obama formed the President's Task Force on 21st Century Policing and charged it with developing recommendations to enhance trust between police and minority communities, as well as to improve police accountability.
The task force final report, published in May 2015, highlighted body-worn cameras (BWCs) as a potential tool for achieving those objectives. Since 2015, the White House and the U.S. Department of Justice have strongly promoted the adoption of BWCs by police.
This is evidenced by the creation of a National Body-Worn Camera Toolkit, a federal funding program that has provided nearly $40 million to more than 175 law enforcement agencies for the purchase of BWCs; podcasts from researchers, subject matter experts, and practitioners (see the BWC Toolkit, page 9); and a training and technical assistance mechanism that helps with BWC adoption and program management.
Advocates and critics have made numerous claims about the benefits and drawbacks of BWCs and, unfortunately, researchers have struggled to keep pace with the widespread diffusion of the technology in American law enforcement. As a consequence, many of those claims have gone untested.
Research on BWCs has grown rapidly, and over the past few years we have learned a great deal about the impact and consequences of the technology. The growing body of research allows us to take a step back and assess the veracity of some of the most important claims about the technology.
Here we tackle five claims about BWCs, and we separate fact from fiction based on the available research.
 [FICTION] Police Officers Don't Like BWCs.
The available research tells us this claim is fiction. Conventional wisdom suggests that law enforcement interest in BWCs emerged after Michael Brown's death in Ferguson, Missouri, in August 2014, but that is not true.
Law enforcement interest in BWCs pre-dates the current crisis in policing by several years. A few law enforcement agencies in the United Kingdom (UK) started experimenting with BWCs as far back as 2005 (Goodall, 2007), and a number of agencies in the United States adopted the technology in 2010-2012 (e.g., Oakland, California; Albuquerque, New Mexico; and Phoenix, Arizona).
Police leadership organizations, including the International Association of Chiefs of Police (IACP), have publicly supported BWCs. The rapid and widespread adoption of cameras is also evidence of the manner in which law enforcement has embraced this technology. While a full accounting of the number of body-worn cameras in use in the United States is elusive, one source estimates that one-third of the approximately 18,000 police departments in the U.S. are using or plan to use body worn cameras. (1)
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 consistently show strong support before officers are assigned BWCs. The support becomes even stronger post-deployment (Gaub et al., 2016; Jennings et al., 2014).
Admittedly, police officers have their own set of concerns about the technology, most notably the nature and frequency of supervisor review. Those concerns are perhaps best illustrated by recent events in Boston, where the Boston police union sought a court injunction to stop the department leadership from creating a BWC program. A superior court judge in Suffolk County denied the union's request. (2)
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 a BWC planning and implementation process that is inclusive of line officers, gives them voice, and allows them to express their concerns. If such a process is followed, officer buy-in for BWCs will likely occur.
 [FACT] Residents Approve Police Adoption of BVUCs.
The available research tells us this claim is fact. BWCs have been publicly embraced by a number of resident advocacy and human rights groups, including the American Civil Liberties Union (Stanley, 2015) and the NAACP, citing their value in promoting transparency and public trust.
Civil rights and advocacy groups certainly have their own ideas about core issues surrounding resident privacy, officer accountability, and public access to video, but in principle, they support the technology. Also, survey research with general population samples shows that residents, as a whole, are strongly supportive of police BWCs (Sousa et al., 2015).
Finally, there has been little research examining the attitudes of people who are most affected by the technology: the residents whose encounters with police are recorded. Their views are critically important, and early research from Spokane, Washington (White et al., 2016a), and Tempe, Arizona (White et al., 2016b), shows that this important subgroup of people is also strongly supportive of the technology.
 [FACT] BWCs Can Lead to Reductions in Police Use of Force and Resident Complaints.
The available research tells us this claim is fact, with some extremely important caveats. The majority of BWC studies have reported significant reductions in these two important outcomes following deployment of BWCs.
For example, 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--post-BWC deployment (Ariel et al., 2015). Similar positive results have emerged from studies in Mesa, Arizona (Mesa Police Department, 2013), and Orlando, Florida (Jennings et al., 2015).
A recent study in Phoenix concluded "if BWCs are employed as prescribed [i.e., 100 percent activation compliance] , a majority of complaints against officers would be eliminated (Hedberg et al., 2016)." Not every single study has reported declines in use of force and complaints post-BWC deployment, but the weight of the available evidence is highly persuasive.
Now to the important caveats. 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.
Ariel and colleagues (2016) examined data from nearly a dozen different police departments in the UK and the United States, and they tied patterns in use of force to officer decisions on BWC activation. 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 resident notification, use of force actually increased by 71 percent. If BWCs are used as intended, the technology can lead to reductions in resident complaints and use of force.
In addition, it is likely that a department with low rates of complaints against officers and high levels of community trust in the police will not experience dramatic changes in police complaint filings post-implementation.
 [FACT] BWCs Generate Valuable Evidence.
The available research tells us this claim is fact. 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 (ODS Consulting, 2011).
Another UK study reported that BWCs led to quicker resolution of cases, less officer time devoted to paperwork, and more time spent on patrol (Goodall, 2007). Morrow et al. (2016) reported that BWCs led to enhanced criminal justice outcomes for domestic violence cases in Phoenix, and a study in Essex, England, reported similar findings (Owens et al., 2014).
Experts have suggested that reductions in resident complaints against officers are explained by the evidence generated through BWCs. A cursory review of BWC footage by a sergeant, for example, can quickly resolve a resident's complaint before it is even filed, either because the complaint is frivolous (i.e., the person declines the opportunity to file the complaint once he or she realizes the incident was filmed) or because the review of BWC evidence shows the officer's actions were justified.
Some police departments have begun documenting the number of officers exonerated from complaints as an indicator of BWC effectiveness. The Las Vegas Metropolitan Police Department (LVMPD), for example, deployed BWCs in 2014-2015. During that time, approximately 70 percent of officers wearing BWCs have been exonerated from complaints as a result of BWC evidence (LVMPD, 2015).
 [FICTION] BWCs Will Always Capture What Happens During a Police-Resident Encounter.
The available evidence tells us this claim is fiction. 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 it may not actually provide evidence about what happened. The view from the camera may be obstructed by the officer's "shooting platform" (i.e., 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 their 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, though audio can still provide critical evidence of what is transpiring, or the device can fall off the officer.
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 insure a bird's-eye view with perfect lighting.
This is not the show COPS. BWCs have limitations, both human and technological. Police, residents, and other stakeholders must be realistic about what BWCs can and cannot do.
* Positive effects of BWCs include officer and resident acceptance, evidentiary value, and reduced resident complaints and officer use of force.
* Authors caution that expectations must be realistic as BWCs have limitations, both human and technological.
* Ariel, B., Farrar, W. A., & Sutherland, A. (2015). The effect of police bodyworn cameras on use of force and citizens' complaints against the police: A randomized controlled trial. Journal of Quantitative Criminology, 31(3), 1-27.
* Ariel, B., Sutherland, A., Henstock, D., Young, J., Drover, P., Sykes, J., Megicks, S., & Henderson, R. (2016). 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, DOI: 10.1007/sl 1292-016-9261-3.
* Gaub, J.E., Choate, D.E., Todak, N., Katz, C.M., & White, M.D. (2016). Officer perceptions of police body-worn cameras before and after deployment: A study of three departments. Police Quarterly, 19 (3), 275-302.
* Goodall, M. (2007), "Guidance for the police use of body-worn video devices", Home Office, London, United Kingdom, available at http://library.college.police.uk/docs/homeoffice/guidance-body-worn-devices.pdf.
* Hedberg, E.C., Katz, C.M., & Choate, D.E. (2016). Body-worn cameras and citizen interactions with police officers: Estimating plausible effects given varying compliance levels. Justice Quarterly, DOI: 10.1080/07418825.201 6.1198825.
* Jennings, W.G., Fridell, L.A., & Lynch, M.D. (2014). Cops and cameras: Officer perceptions of the use of bodyworn cameras in law enforcement. Journal of Criminal Justice, 42, 549-556.
* Jennings, W.G., Lynch, M.D., & Fridell, L.A. (2015). 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 (6), 480-486.
* Las Vegas Metropolitan Police Department. Body Camera Detail. Las Vegas, Nevada: Las Vegas Metropolitan Police Department (April 2, 2015).
* Mesa Police Department. (2013), On-officer body camera system: Program evaluation and recommendations. Mesa, Arizona: Mesa Police Department.
* Morrow, W.J., Katz, C.M., & Choate, D.E. (201 6). Assessing the impact of police body-worn cameras on arresting, prosecuting, and convicting suspects of intimate partner violence. Police Quarterly, 19 (3), 303-325.
* ODS Consulting. (2011). Body worn video projects in Paisley and Aberdeen, Self evaluation. ODS Consulting, Glasgow, United Kingdom.
* Owens, C, Mann, D., & Mckenna, R. (2014). The Essex Body Worn Video Trial. The impact of body worn video on criminal justice outcomes of domestic abuse incidents. College of Policing, Essex, United Kingdom. President's Task Force on 21st Century Policing. (2015). Final report of the President's Task Force on 21st Century Policing. Office of Community Oriented Policing Services, Washington, D.C.
* Sousa, W.H., Miethe, T.D., & Sakiyama, M. (2015). Research in brief: Body worn cameras on police: Results from a national survey of public attitudes. University of Nevada --Las Vegas, Center for Crime and Justice Policy, Las Vegas, Nevada.
* Stanley, J. (2015). Police bodymounted cameras: With right policies in place, a win for all. American Civil Liberties Union, available at https://www.aclu.org/police-body-mountedcameras-right-policies-place-win-all.
* White, M.D., Todak, N" & Gaub, J.E. (201 6a). Assessing citizen perceptions of body-worn cameras after encounters with police. Under review at Policing: An International Journal of Police Strategies and Management.
* White, M.D., Gaub, J.E., & Todak, N. (2016b). Assessing the impact and consequences of police officer bodyworn cameras. Paper presented at the 2016 American Society of Criminology meeting, New Orleans, Louisiana.
ENDNOTES AND RESOURCES:
MICHAEL WHITE, Ph.D., is professor, 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. White worked as a deputy sheriff in Pennsylvania (email@example.com).
JAMES COLDREN, Ph.D., is managing director for justice programs, CNA's Institute for Public Research, Arlington, Virginia; directs CNA's projects pertaining to body-worn camera technical assistance; and is a lead investigator on CNA's randomized experiment with body-worn cameras at the Las Vegas Metropolitan Police Department (firstname.lastname@example.org).
INTERNET INFORMATION Here are additional websites for resources noted in this article:
BJA Body-Worn Camera Toolkit: https://www.bjs.gov/content/pub/pdf/lpd 13et.pdf
BJA Body-Worn Camera Podcast Series: www.bja.gov/bwc/BWCPohttps://www.bostonglobe.com/metro/201 6/09/09/ judge-expected-issue-key-rulingdispute-over-body-cameras-for-boston-police-officers/dGIIBUhuExoNZUpCbJr7JL/story.html
CNA Body-Worn Camera Technical Assistance website: http://www.bwctta.com
Urban Institute information on body-worn camera legislative activity by state: http://apps.urban.org/features/body-camera