'Kyle,' you say, as gently as you can, 'you don't want to do this. I'm not letting you go; you've killed before. I know how it feels, to hold their life in your hands, and to watch it ebb away into the dirt. Do you want to do that?'
You walk up to him, placing a hand on his gun, slowly pushing it down. He seems to take your point; but you feel it, a slight strain in his arm that tells you what he's going to do. Before he pulls the trigger, you draw your weapon, then aim at his neck.
He pulls the trigger, and in a moment of panic you do the same. Pain erupts across your thigh; his bullet ran deep. But it didn't hit anywhere fatal; yours did. From under his jaw, through his mouth, into his brain.
You need to get out of here; that is when you hear the knocks on the downstairs door.