Spoilers..... Well, the whole movie is about the main character going to exact revenge on a guy responsible for the death of his son. Long story short, in the end, the protagonist gets a chance to kill the guy but doesn't and lets him go. The protagonist leaves then gets shot by a government agent but doesn't die. Government agent is about to finish him off but gets shot in the head from the guy he let live saving the protagonist.
RE: QUESTION For Everyone About "KILLING A COP"