I have a cam in my car and at best it captures 35% of incidents. Great if your in front of car as in traffic stops. I always try to stay on cam but to get others to is like herding cats. The cam is not 360 degree.
At least it can gather fragments of an event, and lots of audio, enough to establish much of an incident’s timeline. In this case, it would have at least recorded the perp walking down the center of the street, and much of the ensuing conversation/yelling/screaming/shooting audio.
Hemispherical video wouldn’t be hard to add, capturing 360 degree. Complicated to view, and subject to annoying distortions, but again enough to establish much of what happened and strongly exclude other imputed story lines.