La Voie (D) was driving home from work by himself. An auto with four drunken men drove up behind him and started ramming his car. D stopped his car and got out with a gun. D had a permit for the gun. The four men got out of their car and came toward D, threatening to beat him severely. D shot and killed one of the men. D was charged with murder. The trial judge directed an acquittal of the charge. The People (P) appealed.