“why don’t cops aim for main arm or a leg. guy had a knife, if shot in arm or leg it would have stunned and thwarted advance of guy with knife. police were not in as much life threatening danger from the guy with knife to shoot to kill. I support poilce but some over react unnecessarily.”
You’ve never been attacked have you? Look up Tueller Drill on Youtube. You aim for center of mass and keep shooting until they go down.
Combat soldiers/Marines have been known to say 'They don't pay you to bring back ammo.'