Criminal

You didn't give a shit what was happening to the little girl. You just wanted the world to suffer for what they did to you as a teen. You grabbed the handle of the knife with both hands and twisted it. You could hear bone scraping against the knife and you started to laugh quietly.
Once you had your fun, you pulled out your Magnum and shot her where the Knife was.
Then you pulled the knife out of her throat, cleaned the blood off of it, concealed your gun and walked out of the room.