D lived alone in living quarters which were above a garage. D sometimes slept in the garage and had about $2,500 worth of property there. In March 1970, some tools were stolen from D's home. On May 12, 1970, D noticed the lock on his garage doors was bent, and pry marks were on one of the doors. The next day he mounted a loaded .22 caliber pistol in the garage aimed at the center of the garage doors and connected by a wire to one of the doors so that the pistol would discharge if the door was opened several inches. The two culprits were 15 and 16. Neither of them was armed with a gun or a knife. They returned to the house when D was away and when the 16-year-old, Stephen, removed the lock on the garage and opened the door, he was hit in the face with a bullet from the pistol. Stephen testified: He intended to go into the garage '[for] musical equipment' because he had a debt to pay to a friend. His 'way of paying that debt would be to take [defendant's] property and sell it' and use the proceeds to pay the debt. He 'wasn't going to do it [i.e., steal] for sure, necessarily.' He was there 'to look around,' and 'getting in, I don't know if I would have actually stolen.' D was indicted for assault with a deadly weapon. D admitted to setting up the trap gun. D was found guilty. D appealed. D claims that his conduct was not unlawful because the alleged victim was attempting to commit burglary.