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Research

Body-Worn Camera Toolkit
Description

Although empirical research on the outcomes of the use of body-worn cameras (BWC) has been limited to reduction in the number of community member complaints, correlations have been seen between the use of BWCs and reductions in officer use-of-force incidents. In the United Kingdom, Inspector Steve Goodier of the Hampshire Constabulary says that the extended use of BWCs creates "an elevation in civility of police and community interactions."

Subject matter experts agree that implementing an effective BWC program requires a comprehensive understanding and exploration of key policy, technology, privacy, funding, training, and outreach considerations with direct input from all affected stakeholders, including law enforcement, prosecution, information technology, labor organizations, civic leaders, and community members.

BWC Podcast Series

For more about these topics, please check out the BWC Podcast Series

Go to the Podcasts

To learn more about NIJ’s Research efforts around BWC’s check out:

Subject Matter Experts Share

Featured Resources

Poster for NIJ's Market Survey on Body-Worn Camera Technologies

NIJ releases new BWC Market Survey

 

Read the Survey


Poster for NIJ's Primer on Body Worn Camera Technologies

NIJ releases new Primer on BWC Technologies

 

Read the Primer


Edmonton Police Service

Edmonton Police Service BWC Final Report

Final Report of the Edmonton Police Service Body Worn Video Pilot Project June 2015

Read the Report


Police Officer Body-Worn Cameras

Study Assesses Evidence

OJP Diagnostic Center publishes an assessment of the evidence to inform conversations about the impact, perceived benefits, and important considerations of using police-worn body cameras

Read the Study


Orlando Police Department Executive Summary

Evaluating the Impact of Police Officer Body-Worn Cameras (BWCs):

The Orlando Police Department (OPD) Experience

Read the Executive Summary


Phoenix Smart Policing Initiative

Phoenix, Arizona, Smart Policing Initiative

Evaluating the Impact of Police Officer Body-Worn Cameras August 2015

Read the Evaluation


 

Research FAQs

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Body-worn cameras (BWC) are only one of the tools available to law enforcement for improving community trust, transparency, and accountability. There are several benefits for law enforcement officers who wear BWCs. BWCs provide an additional layer of safety for the officer. Adoption of a BWC program can represent a law enforcement department's effort to demonstrate transparency and accountability. In several studies, community member complaints against officers decreased following adoption of BWCs (Katz et al., 2015; Ariel, Farrar, & Sutherland, 2014; Mesa Police Department, 2013). The results from these studies are supported by in-person interviews with 40 law enforcement executives conducted by the Police Executive Research Forum (PERF). In one study, use-of-force by law enforcement officers decreased following adoption of BWCs (Ariel, Farrar, & Sutherland, 2014). Continuing research seeks to identify the underlying cause of the benefits. Additionally, video from BWCs may assist with prosecution of criminal cases or assist in the review of community members' complaints against officers. While research in Great Britain supports this potential evidentiary benefit, research in the United States has not sufficiently investigated the evidentiary value of BWCs (Goodall, 2007).

During the February 26-27, 2015 Bureau of Justice Assistance BWC Expert Panel, Inspector Steve Goodier of the Hampshire Constabulary in the United Kingdom shared highlights from their yearlong study of 180 body-worn videos. He cited reductions in crime, police-generated incidents, and assaults against police officers. The Inspector further explained "a large-scale public opinion survey was done before and after program implementation that concluded 85% of the public support for BWC technology. This survey was complemented by an officer survey–an overwhelming positive for support for BWCs."

For additional information, see:

Available research consistently shows that officer body-worn cameras (BWC) contribute to a substantial and significant reduction in complaints against law enforcement officers. For example, in Rialto, CA, community member complaints against officers dropped by 88% after BWCs were deployed in the field (Ariel et al., 2014). In Mesa, AZ, BWCs were associated with a 60% decrease in complaints against law enforcement (Mesa Police Department, 2013). In Phoenix, AZ, complaints against officers who wore the cameras declined by 23%, compared to a 10.6% increase among comparison officers and 45.1% increase among patrol officers in other precincts (Katz et al., 2015).

Law enforcement executives agree that BWCs reduce complaints. Former Police Chief Ron Miller of Topeka, KS, stated, "There's absolutely no doubt that having BWCs reduces the number of complaints against officers." (PERF, 2014: 6) The reasons BWCs may cause reductions in community member complaints are not known. During the February 26-27, 2015 Bureau of Justice Assistance (BJA) BWC Expert Panel, Dr. Michael D. White of Arizona State University highlighted the importance of these findings and noted that the cameras may cause improved behavior ("civilizing effect"), may influence community member reporting rates (less likely to file complaints, especially frivolous complaints), or both. A number of law enforcement executives indicated that their officers have observed that BWCs discourage members of the public from filing unfounded complaints. More research is needed (especially in identifying the underlying cause of the benefit), but the consistency of the complaint reduction findings is notable.

BWCs can improve relationships between law enforcement and communities but are not a panacea, and community engagement should occur before or simultaneous to implementation. Joe Perez, President of the Hispanic American Police Command Officers Association - National Capitol Region, stated during the BJA BWC Expert Panel, "in regards to building trust with communities, having a BWC isn't going to build a better relationship with the community. Relationships need to be built before putting on the camera. Just because I put on a camera doesn't mean that it's building a relationship or more trust." Kay Chopard Cohen, Executive Director of the National District Attorneys Association, stated, "If a chief is worried about community relationships, then the chief has to do more than just give an officer a camera. He or she needs to go out and engage the community." Michael Kurtenbach of the Phoenix (AZ) Police Department added, "Develop relationships with the community on the front-end because it's too late to try to make those connections after an incident."

Also during the BWC Expert Panel, Inspector Steve Goodier of the Hampshire Constabulary in the United Kingdom shared highlights from their yearlong study of 180 body-worn videos citing reductions in crime, police-generated incidents, and assaults against police officers. Inspector Goodier further explained that "a large-scale public opinion survey was done before and after program implementation that concluded 85% of the public support for BWC technology. This survey was complemented by an officer survey–an overwhelming positive for support for BWCs.""

For more information, see:

In Rialto, CA, there were 61 use-of-force incidents before deployment of body-worn cameras (BWC) and just 25 incidents after deployment (a 60% drop). Additionally, "control" work shifts (officers who were not wearing cameras) produced double the number of use-of-force incidents compared to "treatment" shifts (camera-wearing officers) during the same period. The study in Mesa, AZ, also found significant reductions in use-of-force among officers wearing cameras, but in Phoenix, AZ, there was no significant difference in use-of-force incidents among camera-wearing and non-camera-wearing officers. Much more research needs to be conducted to determine whether BWCs reduce use-of-force by law enforcement. In addition, the Office of Community Oriented Policing Services Implementation Guide emphasizes that BWCs produce benefits in terms of change in behavior (civilizing effect), but those benefits can only be realized if the community member is aware of the recording.

For more information, see:

There are a number of ongoing studies, many of which are using randomized controlled trial designs. The National Institute of Justice is currently funding studies in Las Vegas (NV) and Los Angeles (CA). The Laura and John Arnold Foundation is funding studies in Spokane (WA), Tempe (AZ), Anaheim (CA), Pittsburgh (PA), and Arlington (TX), as well as a national cost-effectiveness study. A number of other research studies are underway or in the planning stages in the United States and United Kingdom, including Pensacola and West Palm Beach (FL), Orlando (FL), Greenwood (IN), Miami Beach (FL), Oakland (CA), and the Isle of Wight and Essex (United Kingdom).

Currently, we do not have an accurate estimate of the number of law enforcement agencies that have initiated body-worn camera (BWC) programs. Several law enforcement agencies in the United Kingdom were experimenting with BWCs as far back as 2005. In August 2013, the Police Executive Research Forum (PERF) surveyed 500 law enforcement agencies regarding their use of BWCs. Of the 254 agencies that responded, just 25% (n=63) indicated that they deployed BWCs. Interest in the technology has grown tremendously since then. One BWC vendor advertised in February 2015 that its product has been purchased by 4,000 law enforcement agencies worldwide, but this figure has not been verified. One expert has estimated that between 4,000 and 6,000 law enforcement agencies are planning to adopt or have already adopted BWCs. The Bureau of Justice Statistics (BJS) is performing a survey to better understand the number of law enforcement agencies that have implemented a BWC program.

For additional information, see:

Yes, there is some evidence that suggests that body-worn cameras (BWC) improve the likelihood of successful prosecutions. In Phoenix, AZ, a Bureau of Justice Assistance-sponsored project examined the impact of BWCs on domestic violence case processing, concluding the following: "Analysis of the data indicated that following the implementation of body-worn cameras, cases were significantly more likely to be initiated, result in charges filed, and result in a guilty plea or guilty verdict. The analysis also determined that cases were completed faster following the implementation of body-worn cameras, (in part because of the) addition of a court liaison officer who facilitated case processing between the Phoenix (AZ) Police Department and city prosecutor's office." (Katz et al., 2015)

Agencies have varied considerably in the content and structure of their department policies. Many agencies have made their policies publicly available, or they will furnish their policy upon request. A number of policies have been collected by the Bureau of Justice Assistance and are available in this toolkit. In addition, there are currently several model policies available for review. The International Association of Chiefs of Police has devised a model policy. The Police Executive Research Forum (PERF) report (PERF, 2014) also includes a number of policy recommendations. In the United Kingdom, policy resources are available through a United Kingdom Home Office report (Goodall, 2007).

For more information, see:

There has been little research conducted on the effect of body-worn cameras (BWC) on criminal prosecutions. In Phoenix, AZ, researchers found that domestic violence cases involving a camera-wearing officer were more likely to be initiated by the prosecutor’s office (40.9% vs. 34.3%), have charges filed (37.7% vs. 26%), have cases furthered (12.7% vs. 6.2%), result in a guilty plea (4.4% vs. 1.2%), and result in a guilty verdict at trial (4.4% vs. 0.9%) (Katz et al., 2015).

The Plymouth (England) Head Camera Project reported that the technology increased officers’ ability to document that a violent crime had occurred, and the incidents recorded by BWCs were more likely to be resolved through guilty pleas rather than criminal trials (Goodall, 2007). In Renfrewshire, Scotland, BWC cases were 70-80% more likely to result in a guilty plea, compared to other court cases. A more recent report from Essex, Scotland, that focused specifically on domestic abuse calls also found that criminal charges were more likely to be filed in cases where an officer was wearing a BWC (Owens et al., 2014).

Anecdotal evidence from the Police Executive Research Forum (PERF) interviews of law enforcement executives (PERF, 2014) also suggests that BWCs may affect prosecution of cases through improved evidence collection. Chief Parker of the Dalton (GA) Police Department reported that BWCs have enhanced evidence collection at accident scenes, as officers work to secure a scene, interview witnesses and victims, and provide emergency medical care as needed. Several chiefs also indicated that BWCs are useful in domestic violence cases when it is difficult for a victim to participate. In these cases, BWC policies regarding victims, to include children and other vulnerable persons, must be carefully crafted.

For more information, see:

There are a handful of useful resources on body-worn cameras (BWC). The Police Executive Research Forum (PERF) and the Office of Community Oriented Policing Services (COPS) Office published a report in 2014 that examines key issues and offers policy recommendations. The report is based on survey responses from 254 agencies, interviews with 40 law enforcement executives who have implemented BWCs, and outcomes from a one-day conference held on September 11, 2013, that included more than 200 law enforcement executives, scholars, and experts. In April 2014, the Office of Justice Programs Diagnostic Center published a report that describes the core issues surrounding the technology and examines the state of research on those issues (White, 2014). In March 2014, the National Institute of Justice (NIJ) published a market survey that compared BWC vendors across a range of categories. There is also a growing number of published evaluations that examine the implementation, impact, and consequences of body-worn cameras. This web site and toolkit is intended to be a clearinghouse of the latest available research, reports, and knowledge on the technology.

For additional information, see:

For additional evaluations from around the United States, United Kingdom, and Canada, see:

Or view BWC Toolkit Research Resources with the category of Implementation Experiences

There is little empirical evidence on the impact of body-worn cameras (BWC) on community member complaint investigations. In Phoenix, AZ, researchers reported that camera-wearing officers who received a complaint were significantly less likely to have the complaint sustained, compared to non-camera-wearing officers and other patrol officers (Katz et al., 2015). Evidence from the United Kingdom also suggests that BWCs may result in quicker investigation of community member complaints against law enforcement (Goodall, 2007). The video evidence may also be used to provide members of the public with additional information that helps them understand the law enforcement officer’s behavior during a particular encounter (e.g., educational value). Legal scholar David Harris stated, "If citizens can see that they were, perhaps, mistaken, or that they did not understand the situation from the officer’s point of view, or that they did not have all the facts, they may come away with a better grasp of the situation, and feeling that they need not continue with the complaint process." (Harris, 2010: 7)

There is also some evidence to suggest that BWCs can assist with the investigation of critical incidents, including officer-involved shootings. Former Chief of Police Miller of the Topeka (KS) Police Department stated that a local district attorney cleared one of his officers of any wrongdoing during a critical incident after reviewing the BWC footage of the deadly shooting (PERF, 2014).

For more information, see: