If it were real, I doubt he'd be going to jail.  I think Drunky is pretty close to correct on this subject.  One of my friends killed his stepdad.  The guy was beating his mom had a gun, and my friend shot him, I think it was 7 times.  Spent a month with the county.  Never did anything after.  It's in self defense, he's scared, he doesn't know if he is going to pick up that gun again and shoot him.