The Calibre Report: Body Cam vs. Dash Cam

From The Calibre Report published by Calibre Press.
To subscribe, please e-mail:

Civilians tend to judge an officer’s actions more leniently when they see a body cam recording of an incident than when they watch the same event on dash cam footage, according to a Northwestern U. research team.

Because of the weight the public gives to video evidence in assessing police “accountability” these days, this finding could have significant legal and public relations implications.

Indeed, in one experiment volunteers acting as mock grand jurors were asked to decide whether an officer should be indicted for an encounter on a traffic incident that unintentionally turned bad. Those who watched the incident on dash cam were highly more likely to recommend a charge of assault, battery, or aggravated battery than those who viewed footage from the officer’s body cam.

There appears to be a “diminished sense of blame or responsibility for the person who’s wearing the body cam,” says Dr. Neal Roese, an NU professor both of psychology and marketing and an internationally recognized expert on the psychology of judgment and decision-making. A body cam wearer’s intentions seem to be regarded differently, he explains—an important distinction in the legal arena, where intentionality can be a pivotal consideration.

A full account of the researchers’ work has been published under the title “Body camera footage leads to lower judgments of intent than dash camera footage” in the Proceedings of the National Academy of Sciences. A layman’s synopsis of the findings from a Northwestern newsletter is here.

Unstudied consequences. The research was initiated by Broderick Turner, a PhD candidate at Northwestern’s Kellogg School of Management, who in his private life had developed a curiosity about the pervasiveness and power of surveillance video in controversial police encounters.

“Despite the widespread use” of body cams and dash cams, he writes, “little is known about [their] specific impact on judgments.” Because “most police videos used in court depict negative outcomes,” there’s an obvious motivation “to avoid blame for [that] outcome.” But in that effort, he wondered, is all footage equal? Or might video from different types of cameras be perceived differently? And might these differences affect how an officer’s actions are evaluated?

Along with Prof. Roese and two other researchers, Turner recruited an online test pool of about 2,000 US-based civilian volunteers and exposed random groups of them to different experiments involving real-world police videos from YouTube, plus a few staged films created specifically for the study. Across eight experiments, 26 videos total were involved, all played without sound.

Varied scenarios/same outcome. One test, for example, involved two real-life films in which an officer shoots a suspect and one in which an officer breaks a window of a driver’s car. Dash cam and body cam versions of each incident were shown, edited to have the same start-start moments and to be of identical duration.

Each volunteer then rated the involved officer on a sliding scale as to:

• whether he/she acted intentionally (from “strongly disagree” to “strongly agree”),

• how much blame the officer deserves (from “none” to “a great deal”), and

• how much the officer should be punished (from “not at all” to “a great deal”).

Results were consistent. Viewers who saw the body cam footage judged the officer as “less intentional,” thought he deserved less blame, and called for lighter punishment than those who saw the dash cam video.

Why? Seeking an explanation, the researchers initially speculated that perhaps “body cam footage invites the viewer to take the wearer’s perspective;” that is, seeing the action from the officer’s point of view might create an empathy that favors the officer.

But further experimentation led the team to a much different—and less logical—conclusion. What really seemed to make the difference, the study found, is that “body cams typically contain fewer visual indicators of the focal actor [the wearing officer], which decreases attention to that actor.” Dash cams, with their “third-person perspective,” tend to render “the actor’s body more visually prominent.”

In identifying the importance of what the researchers refer to as “visual salience,” they created videos in which body cam wearers were “overtly intentional”—tipping things over, dropping things, kicking things, etc. Some of these videos showed no part of the camera wearer’s body, while in other versions the wearer’s arms or feet were visible.

Where viewers could see sustained parts of the wearer on body cam footage, the body cam lost its judgmental edge over the dash cam regarding intentionality. In short, the usual difference in viewer reaction to body cam vs. dash cam was “mitigated.”

That may be, the study speculates, because showing body parts can reveal an officer’s dynamic movement and convey “additional information about how the incident unfolds in real time, including subtle cues as to the [officer’s] mental state.”

“Jurors” speak. Of particular interest in the study is the mock jury experiment. Here about 200 volunteers pretending to be grand jurors considered a real-life case in which an officer approached a vehicle stopped in traffic, with a driver who apparently had passed out. Unable to rouse the driver, the officer broke a passenger-side window, “startling the driver, who then accelerated suddenly and crashed” into a power pole, starting a fire.

All participants read the officer’s report. Some also watched body cam footage of the incident, while some others watched a dash cam recording. When all then voted on whether to indict the officer on criminal charges, the differences were striking:

• Over 70% of the dash cam viewers wanted to send the officer to trial for assault, while less than half of the body cam group voted to;

• Nearly 70% of dash cam viewers favored indictment for battery, compared to 53% of the body cam group;

• 60% of the dash cam watchers called for a charge of aggravated battery vs. less than half of those who saw body cam footage.

Interestingly, “jurors” who only read the officer’s official report but saw no video tended also to be significantly more likely to vote for indictment.

“When body cam [footage] is included, the mean odds of indictment decrease,” the researchers conclude. “[T]his research suggests that viewing body cam footage might make judgments by jurors and as well by the general public more lenient toward the body cam wearer [and] might in some cases reduce the likelihood that grand juries will indict a police officer, compared with dash cam video or a written report of the incident.”

The team emphasizes, however, that more research on video impact is urgently needed. “For society to benefit most from the greater transparency conferred by emerging forms of surveillance, these advances in technology require corresponding advances in our understanding of their effects on observant judgment.”

Our thanks for Lt. Glenn Mills, president of the Massachusetts Assn. of Crime Analysts, for alerting us to this study.

To sign up for the free Calibre Report, subscribe below.

#mc_embed_signup{background:#fff; clear:left; font:14px Helvetica,Arial,sans-serif; }
/* Add your own Mailchimp form style overrides in your site stylesheet or in this style block.
We recommend moving this block and the preceding CSS link to the HEAD of your HTML file. */


* indicates required


(function($) {window.fnames = new Array(); window.ftypes = new Array();fnames[0]=’EMAIL’;ftypes[0]=’email’;fnames[1]=’FNAME’;ftypes[1]=’text’;fnames[2]=’LNAME’;ftypes[2]=’text’;fnames[3]=’ADDRESS’;ftypes[3]=’address’;fnames[4]=’PHONE’;ftypes[4]=’phone’;}(jQuery));var $mcj = jQuery.noConflict(true);

Subscribe To Our Newsletter

Join the 125,000+ law enforcement professionals who receive the weekly Calibre newsletter filled with analysis of force encounters caught on video, training articles, product reviews, expert commentary and more.




Submit a Comment

Your email address will not be published. Required fields are marked *

Related Posts

Reframing De-escalation

Reframing De-escalation

“The body does keep score.” Powerful Feedback From a Calibre Newsletter Reader

“The body does keep score.” Powerful Feedback From a Calibre Newsletter Reader

Take Notice of an Officer’s Pain

Take Notice of an Officer’s Pain

Continued: Cops & Mental Illness Calls: Can We Break the Cycle?

Continued: Cops & Mental Illness Calls: Can We Break the Cycle?

Cops & Mental Illness Calls: Can We Break the Cycle?

Cops & Mental Illness Calls: Can We Break the Cycle?