The Science Behind Where Police Should Place Their Body Cameras

The Science Behind Where Police Should Place Their Body Cameras
As law enforcement increasingly uses body-worn cameras, researchers are studying the roles of camera design and perspective.


(Inside Science) -- Joel Suss, an Australian psychologist, had just arrived at Wichita State University in 2015, at a time when the U.S. media was becoming increasingly focused on police shootings. An expert in applying what's known as human factors to law enforcement, Suss studies how officers respond physically and psychologically to different environments, such as how well an officer fires a gun while under stress. He wanted to make contacts inside the local police department, so he signed up for the citizen police academy.
While enrolled, he heard about some research being done internally by the Wichita Police Department. Captain Brian White had mounted body-worn cameras on different parts of a police officer and recorded shooting drills. They wanted to figure out the best camera position for the diverse scenarios police officers often encounter.
Intrigued by the department's human factors problem, Suss asked White if they could repeat the experiments, keep a bit more data and expand the scope of the experiment -- the police department had limited the scope of their initial tests and hadn’t kept the records after they finished.
Testing body cameras
That new study, recently published in the journal Ergonomics in Design, is the first, to Suss’s knowledge, to approach police body cameras from a design and ergonomics perspective. It’s just one example of the ways researchers are starting to delve into the bigger questions associated with body cameras, from artificial intelligence analysis to perspective bias.
In the study, Suss and his colleagues recorded three officers each completing 35 live-fire drills, in which they fired at a static paper target using three weapons they could potentially use in the line of duty -- a handgun, patrol rifle and shotgun. The researchers varied the officers’ starting position (facing the target, turned away from the target), shooting stance, and one- or two-handed grip. Four officers also engaged in live role-playing scenarios including domestic disputes, ground fighting, traffic stops, and pursuits on foot or in a vehicle. The team painstakingly analyzed each frame of the footage, assessing what the video showed at any moment.
In one scene, for example, an officer faced away from the target and then had to turn.
“If you could imagine that we've got cameras on the head and we've got cameras on the body, the head swivels first so head-mounted cameras gave a better perspective or captured more of the target than the ones on the body,” explained Suss.
He also found that mounting cameras on the shoulders, epaulettes or collars actually changed the structure of the shoulders. “So sometimes when that happens, the camera that's on the shoulder ends up pointing down at the ground,” he said, “not at the target.” Suss says they plan to calculate overall proportions of target visibility for each camera-mounting position by averaging across drills, weapon types and officers.
While the results are preliminary, the paper does lay out a few recommendations. The researchers say camera-mounting positions on the head -- like glasses or baseball cap -- appear to provide a more complete view of the target than those mounted on the torso. It also seems that the torso-mounted cameras are less stable than those mounted on the head as they can be altered or obscured by officers lifting their arms.
The largest maker of police body cameras, Axon, makes different magnetic camera mounts, so police officers can actually move the camera around to different positions -- glasses, shoulders, cap, or chest. Suss says it allows a lot of flexibility -- an officer could quickly move the camera before entering a situation. But sometimes these mounts can pop off, especially in situations where a police officer is in a fight on the ground.
Body-worn cameras -- at least, those made by Axon -- are rolling all the time. But they only retain so-called events when an officer double taps a large button in the center of the lipstick-sized camera. Guidelines vary by agency, but officers are generally supposed to record when they enter a situation about which they could end up writing a police report. When activated, the camera keeps the previous 30 seconds of video, and anything going forward. Even when they’re used infrequently, it still adds up to hundreds of thousands of hours of footage each day for large police departments. (The London Metropolitan Police Service, for example, has 22,000 body-worn cameras.)
written by dh