When New Jersey police went to the wrong house to investigate a 911 hang-up call they shot resident 76-year-old Gerald Sykes, who called 911 to let them know he'd been shot. The police sent to investigate the shooting did not shoot Skyes.
From NJ.com:
The New Jersey Attorney General's Shooting Response Team which is investigating the shooting said two uniformed officers were sent to the house in error. After no response at the front door, they went around back to a deck where they knocked and announced themselves, according to the investigation. Then there was "an exchange of gunfire" with one trooper firing four rounds and Sykes firing one round.
The state does not say who fired first. Sykes' family say police fired and then Sykes — armed with a shotgun with birdshot in it to wound intruders but not kill them — shot back, thinking those on his deck were intruders.