The cop that was there was shot dead
Didn’t you comment earlier thst the citizen didn’t/wouldn’t have had time to call police and identify himself because more cops were already there when he shot the suspect? Which is it?
In a situation where officers are already on scene , a smart CCW holder does not get involved unless there is no other option and/or he has already identified himself to the officers on scene.
If there are no officers on scene, then the civilian gun owner needs to make their presence and lack of threat known to responding officers as soon as they arrive, if not before they arrive.
In either case, they should not be interfering with evidence. Especially not items that might lead officers to confuse them with the suspect.