Head, shoulders, chest: Does mounting location affect visibility of key information in police body-worn-camera footage?
Body-worn cameras are becoming commonplace in law enforcement. Much of the research related to them focuses on whether the cameras affect police officer behavior and the number of citizen complaints against police. Relatively little attention has been focused on human factors and ergonomic issues related to the deployment of body-worn cameras. One ergonomic issue concerns where they are mounted on the body. This is an important issue, as the mounting location could affect the quality of the recorded footage. As there is little current evidence-based guidance on optimal mounting locations, we examined the differences in target visibility for various body-worn camera mounting locations. Three officers performed 31 different live-fire drills at a static target using a handgun, patrol rifle, and shotgun. The drills varied in starting position, stance, grip, and movement. Body-worn cameras were mounted on both sides of each officer’s hat, glasses, and shoulders, as well as in the conventional chest position. A camera was also mounted on each firearm. Each drill was divided into pre-firing, firing, and post-firing phase as well as an aggregate across all phases. The percentage of frames where the target was fully visible according to each camera was coded and used as the primary outcome. Overall, across all phases, the head-mounted cameras (hat and glasses) and the chest-mounted camera had superior visibility (~80 % fully visible) compared to firearm-mounted (68 % fully visible) and shoulder-mounted (~12 % fully visible) cameras. During the pre-firing phase, all head-mounted cameras (hat and glasses) had superior visibility (~70 % fully visible) compared to all other mounting locations (14-41 % fully visible). This investigation suggests that head-mounted cameras—either on the left or right side of a hat or glasses—are superior for optimizing target visibility.