Over the last few days an off duty policeman was attacked by five armed scum and only survived because when he was shot at, the bullets never left the chamber and in another incident, an off duty policeman and his wife were attacked while riding home on his motorcycle. On that occasion he managed to shoot dead one of the assailants and has not been detained as the judge considered it to be legitimate force. He was lucky in that respect because so many of the criminals end up being treated as victims.
Here's the story at TN.