The Impact of Body-Worn Cameras on the Burden of Proof 

Thomas Woodmansee, Senior Advisor, CNA, and former police officer

A Police Perspective

Perhaps no other new technology in American policing history has created such high expectations of establishing police credibility and accountability as have body-worn cameras (BWCs).  But what impact will such expectations have on investigations and trials? In discussions I have had with law enforcement officers around the country, I have learned that most officers understand and appreciate the public’s need for transparency but are also concerned that BWC footage, or lack thereof, will become the predominant factor in validating or invalidating their decisions and actions. 

Unlike DNA, which leaves little room for interpretation—other than by scientists, who cite statistical probabilities—body-worn camera footage is just a snapshot of an event and captures only a portion of what has occurred. It does not capture all the nuances or experiences of a scene or event, such as the officer’s knowledge of a place or person; emotional factors, including the danger of a call; or environmental influences, such as sounds or sights beyond the range of the lens.

Also, viewers respond subjectively to BWC footage. After 25 years in law enforcement, I have not come across any other profession about which so many people who have never done the job want to say, “this is how I would have done it.” People tend to insert themselves into the BWC footage and project how they think the officer should have acted.  Their projections, of course, will not be based on experience or training but likely on emotion—I have seen it happen even when officers see other officers’ BWC footage.

Law enforcement agencies are finding, however, that BWC footage often ends up validating the good work done by their officers, supporting officer accounts, and/or refuting suspects’ versions of events. Like recordings of felon interviews—a technology I initially feared would inhibit investigations—BWC footage can enhance and support cases and become an invaluable tool.

As BWCs become more prevalent as a law enforcement tool (approximately 4,000–6,000 of the 18,000 law enforcement agencies in the United States have adopted or are adopting BWCs),[1] expectations to produce video evidence for every police investigation will certainly rise.  From hair and fiber analysis to fingerprints and DNA and to audio and video recordings, technological advances have consistently raised expectations for police to produce evidence beyond their own observations, investigations, and reports.  Consider the following:

  • After radar was introduced as a speeding law enforcement tool in the 1950s, police could no longer cite “training and experience” for their probable cause estimating speeds. Radar proof became an expectation for citation and conviction. 
  • Fingerprints and DNA have helped both to prove guilt and to exonerate those who were mistakenly charged and/or convicted. Police now understand that they are expected to demonstrate the presence, and/or explain the absence, of DNA and fingerprints.

Will the availability of BWC evidence create an expectation that all police reports be supplemented with BWC footage? Will prosecutors and juries come to expect, or even demand, BWC evidence to charge and convict?

The ever-popular “CSI effect”—television’s influence on society’s expectation that evidence such as DNA can and should be gathered on everything and processed within hours, if not minutes, and lead of course to automatic confessions and convictions—also affects public understanding of BWC evidence. Police and prosecutors are acutely aware of this effect; I have seen them address the issue directly with juries to establish realistic expectations about evidence.


According to a national survey of state prosecutors conducted by George Mason University, 67 percent of prosecutors surveyed expressed extreme concern about the potential influence on a trial of a lack of BWC footage because of juror expectations that this evidence will be provided.[2] If concerns about such an influence are valid, what, if anything, can be done?

Policy and Training. Law enforcement agencies implementing BWCs should provide vigorous and comprehensive training programs that emphasize compliance with BWC activation and that articulate that a lack of expected footage can impact the outcome of an investigation, arrest, and prosecution.  Agencies should promote the fact that detailed BWC policies and trainings benefit officers, the agencies, and the communities they serve.

Collaboration with Prosecutors. Law enforcement agencies should engage with their city, state, and federal prosecutors on the expectations of BWC evidence.  Agencies should use their prosecutors for BWC training and in-service updates.

Outreach and Education. Best practices in BWC policy development include engaging and collaborating with both external and internal agency stakeholders. This outreach should include dialogue and information about the fact that BWC footage cannot capture the totality of an investigation or incident.

Take Advantage of the Camera. Some law enforcement agencies activate BWCs while conducting radar and use the footage to enhance their evidence. Some train their officers to “talk to the camera” when responding to a call to provide a more comprehensive perspective of the environment. Through this practice, officers provide a verbal narrative of what they are seeing and experiencing beyond what the BWC can capture, of course keeping tactical safety considerations in mind.

Report Writing. The limitations of BWC footage increase the need for more thorough and detailed report writing to articulate what the footage did not capture. Law enforcement agencies should continue with thorough, detailed reports and not assume that BWC footage will be the ultimate narrative of the call.

The Human Impact. Law enforcement agencies should be aware that what an officer sees, feels, and recalls may differ from what is captured on the BWC. Officers must also accept that the camera does not capture everything. If an officer does not recall seeing what the camera captured, the officer should document this in the report and transparently acknowledge what he or she did and did not see at the time of the incident.

Law enforcement officers have always demonstrated a remarkable ability to adapt to change—whether it arises from shifting community needs and expectations or from new laws, policies, tactics, or technologies.  BWCs may impact society’s expectations about evidence, but law enforcement agencies can address this problem by establishing sound policies; providing officers with up-to-date trainings on BWC operations, compliance, and best practices; and educating the public about limitations and reasonable expectations of the footage captured. 

[1] “Body-Worn Camera Frequently Asked Questions,” Bureau of Justice Assistance, 2015, p. 2,

[2] Center for Evidence-Based Crime Policy, A National Survey of State Prosecutor’s Offices (George Mason University, 2016), p. 23.

Thomas Woodmansee, Senior Advisor, CNA, and former Lieutenant for the Madison, WI Police Department. Prior to joining CNA, he worked for the Madison, WI Police Department for 25 years.Mr. Woodmansee's experience includes:  Patrol Officer, Undercover Narcotics Officer, and 13-years as a Detective.  He also served on the SWAT team as a tactical operator, later as a Negotiator and then a Commander and oversaw the police Academy and several specialized investigative units. Mr. Woodmansee has worked with many agencies around the country on a variety of projects and systems improvements through BJA Smart Policing Initiative and BJA Violence Reduction Network.