Ok.. Get the pit bull AND the used 12 gauge..
Chain the pit bull to the outside of the house...
When the guy comes back the pit bull will attack and kill the intruder, so you dont go to jail for murder.
Once the pit bull has attacked and killed the man, you go outside and shoot the pit bull so you dont have to take it to the vet or feed it.. (the cops are prolly gonna put it down anyway)
Problem solved.