You get downvoted because you are ignorant. Using a gun to defend yourself is fine. This guy waited until the perpetrator was on his way out the door (didn't bother helping anyone before that), then shot him in the back when most likely everyone was already safe from danger because the perp was leaving. Then he went ahead and went full on murder mode and continued what is a blatant execution, ending with a shot to the head to an unarmed man.

The reason the 'libs' don't like things like this video is because that man fucking executed someone after shooting him in the back like a little bitch, and you morons are cheering him on. You are the the type of person who absolutely should not have access to guns because your reasoning skills are so low they are below the ground.