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What Body Cams Do: Behavior, Accountability and Trust

Five years after the killing of Michael Brown, has the widespread adoption of body-worn cameras by U.S. police departments changed the factors that led to his death, and the subsequent protests?

Editor's note: This is the third part in a series about body cameras in the U.S. To follow along with the series, click here.

Michael Brown is far from the only unarmed African American to be killed by police in the U.S. this decade; he was one of many whose deaths sparked grief and communal outrage and distrust of law enforcement in general. But it was this killing, in 2014, in particular that appears to have sparked the rise of body cameras across the country.

So, five years later, has the technology changed the circumstances that propelled it into popular use?

If body cameras were supposed to provide an undisputable record of the truth — thereby holding officers accountable when they unlawfully kill civilians — then the results have been a mixed bag. And if they were meant to prevent killings and violence from ever happening, it appears they have failed.

In fact, the clearest beneficiary of body cameras has been police agencies themselves. In the coming days, Government Technology will examine what research, experts, advocates and police say body cameras are and aren’t good for.


It doesn’t appear likely that body cameras cause big changes in police behavior.

Research on the question has turned up mixed results. Many studies of varying quality have been conducted on the question; some have found that officers wearing cameras were less likely to use force while many found no difference with the cameras. RAND Corp. and a George Mason University research team both found that officers whose cameras are turned on for their entire shift are less likely to use force than those who have discretion over when to turn them on, or who are only required to turn them on under certain circumstances.

There are those who believe that they lead police to behave more politely in certain situations, such as when dealing with a person who is being rude — for pragmatic reasons.

“Generally the officers use the video to their benefit to demonstrate professionalism, especially if somebody’s getting out of hand,” said Grant Fredericks, an expert witness in cases involving video evidence and owner of a testing lab for body cameras. “They know they’re recording, they know they’re going to look good in court … and the bad guy’s going to look bad.”

But does the presence of a camera change the actions officers take in the heat of the moment? Police and experts seem skeptical.

They certainly don’t expect officers to admit it.

“We haven’t had any occurrence in the department where an officer said, ‘I didn’t want to do something because the camera was on,’” said David McNeil, chief of the Aberdeen, S.D., Police Department. “Haven’t seen any hesitation in that respect.”

Scot Esdaile, who sits on the National Association for the Advancement of Colored People’s board of directors, said things don’t seem to be getting better. If anything, he feels there’s been more police violence against communities of color.

And it’s not like cameras are new when it comes to police misconduct either. It’s been nearly 30 years since the Los Angeles Police Department’s beating of Rodney King was captured on video tape. The initial acquittal of the officers involved — two of them were later convicted in federal court — caused mass outrage and disruption too. Just like in Ferguson, and Milwaukee, and Sacramento.

“Whether it’s on camera or off camera, they don’t seem to be changing their behaviors,” Esdaile said.

As body cameras have become more popular, the number of police killings of civilians has not substantially changed. According to data compiled by The Washington Post, there were 994 fatal police shootings in the U.S. in 2015, the year body cameras really started taking off in law enforcement. In 2016, there were 962 fatal police shootings. In 2017, there were 986. In 2018, there were 992.


In July 2016, officers in Baton Rouge, La., shot and killed Alton Sterling, who had a gun on his person. In August 2017, officers in Salt Lake City shot and killed Patrick Harmon, who had a knife that they said they believed he was reaching for. In March 2018, police shot and killed Stephon Clark in Sacramento, Calif., apparently believing at the time that he was carrying a gun — which was actually an iPhone.

All of those cases involved black men. All were captured by body cameras. All resulted in investigations of the officers involved. All led to protests from community members accusing the police of pulling the trigger too quickly. None so far have resulted in charges for the officers.

They are only a sampling of all the times officers have shot African Americans in the U.S. in the past several years, an event that happens far more frequently per capita than for other racial groups. And though many of the shootings are captured on video — from body cameras, police car dash cameras, nearby security cameras or cellphones — few result in charges being brought against officers, and even fewer result in the conviction of an officer. The conviction of an officer in Balch Springs, Texas, last year for the murder of a 15-year-old African American boy received national attention precisely because of its rarity.

Not that officers should be convicted in every case. Like with any killing, it is up to courts and juries to decide whether they were justified under the law.

The calls for cops to wear body cameras were at least partially based on a hope that they would help juries see when officers were not justified. But the proliferation of video evidence in those cases — from body cams, as well as camera-equipped smartphones — doesn’t seem to be changing much in that regard. At least one study that surveyed prosecutors found that the majority of them use body camera footage primarily to try citizens, not officers. 

There are a variety of reasons. One of them is that the cameras, though they produce evidence a juror can see for themselves rather than taking the word of an officer or witness, are not all-knowing arbiters of truth.

No, a camera catches a particular moment in time within a limited frame pointed in one direction, and it does so at a given frame rate and resolution.

The frame rate is very important in determining how a jury and court should interpret a video. That’s the opinion of Fredericks, who runs a lab that tests body cams for police departments that want to purchase them and who has served as a video interpretation expert on both sides of court cases involving officers shooting civilians.

A slower frame rate — say, below the standard 30 frames per second — can make motions captured on video look faster. That means a fist swung at a person, for example, will look like it was thrown with more force than it actually was.

Then there’s the problem of blurriness, which is exacerbated under the circumstances that many officer-involved shootings happen in. That blurriness can make it hard for a police captain, a district attorney, a Justice Department official, a juror, a judge or a community member to see the exact conditions under which an officer decided to shoot.

“About two-thirds of all public contact with police is going to occur at night, usually when it’s dark, usually outside,” Fredericks said. “And body-worn cameras are designed to be worn on the uniform and (most videos) are going to be shot when the officer’s in motion.”

Another problem is that cameras don’t capture what will often amount to the most important question in a case involving an officer shooting: What was the officer who pulled the trigger thinking?

In order to bring charges or convict an officer, it doesn’t necessarily matter whether the person they killed was actually armed. It doesn’t matter whether the person actually meant to threaten the officer. What matters is whether the officer believed that they were armed; that there was a threat.

Hence, an iPhone becomes a legal justification for killing. The presence of a camera won’t change that.


Since body cameras pushed into law enforcement amid an atmosphere of skepticism and criticism of police departments, it’s worth asking — independently of whether they’ve had concrete impacts on behavior, transparency or accountability — whether they’ve done anything to repair relationships between the police and the policed.

The answer is a big “maybe.”

In 2017, researchers from Florida Atlantic University published findings from a survey in Palm Beach County, Fla., where the West Palm Beach Police Department had deployed body cameras. They found that the “vast majority” of respondents thought the cameras would improve safety for both officers and residents, make policing more legitimate and help the behavior of both police and civilians. Those who had an unfavorable view of the police, however, were less likely to think the cameras would make a difference than those with a more positive view of the police.

A 2017 survey from Penn State Harrisburg of Pennsylvania found that about 88 percent of respondents would feel more safe around a police officer if the cop was wearing a camera. Non-white respondents were more likely to agree with the statement than whites.

Another 2017 survey from Pew Research Center found that 93 percent of respondents favored police wearing body cameras. 59 percent thought cameras would make members of the public more likely to cooperate with officers, and 66 percent said they would make officers more likely to act appropriately. Police in the survey were less likely to think the cameras would make a difference and less likely to support their use.

Few people are positioned more centrally between a community and a police department with a historically bad relationship than Lisa Judge. Judge is the inspector general for public safety in the city of Seattle, which entered into a consent decree with the U.S. Department of Justice in 2012 because of what the DOJ described as a pattern of excessive force by the Seattle Police Department.

Judge thinks the department’s cameras, which it began testing in 2016, are sending the right message and providing some level of accountability and transparency to the city’s minority communities, bringing them into the process. But it’s not a magic bandage.

“My experience right now is that it’s a mixed bag and that there is still work to be done to really make all the segments of Seattle communities feel like they’re invested and enfranchised,” she said.

Liana Perez, director of operations for the National Association for Civilian Oversight of Law Enforcement and a former independent police auditor of Tucson, Ariz., for 17 years, said a lot of people in that city haven’t really engaged in the process. But those who have — by serving on the community oversight board, for example — have found that the cameras give them a better understanding of police work.

“I believe it has really opened their eyes to what the officers are dealing with on a day-to-day basis … I think it kind of builds a bridge between the community and the police department,” Perez said.

Michael Gennaco, a consultant whose firm is contracted to provide independent oversight of several police agencies, said body cameras have mixed results when it comes to building trust between police and communities. Many see them providing more accountability and transparency; many feel uncomfortable with having their faces recorded and feel the cameras are used more as a sword to be swung against citizens than as a shield to protect them from unruly officers.

He sees another possibility: That in some communities, where officers have been filmed killing civilians and walked away without consequences, that people have begun to doubt that the cameras are making things better.

Regardless, Gennaco thinks that community members would feel a lot better about body cameras if they had control of, or at least input on, the policies governing how the departments use them.

“(It doesn’t happen) often enough. I think it’s rare that there’s input, and even when there is input it doesn’t mean that the community voices are implemented,” he said.

Ben Miller is the associate editor of data and business for Government Technology. His reporting experience includes breaking news, business, community features and technical subjects. He holds a Bachelor’s degree in journalism from the Reynolds School of Journalism at the University of Nevada, Reno, and lives in Sacramento, Calif.