Lyerla (defendant) became enraged while driving his car on an interstate highway when the driver of a pickup truck would not let him pass. Lyerla decided to leave the interstate and exited but changed his mind when he saw that the truck had stopped nearby. Lyerla loaded his pistol, reentered the interstate, and passed the truck. When the truck tried to pass him, Lyerla fired three shots at the passenger side of the truck. Jensen, the driver, was killed by one of the bullets, but two other girls riding in the truck were unharmed. Lyerla was charged alternatively with first degree murder and second degree murder for the death of Jensen and with two counts of attempted first degree murder and attempted second degree murder of the other two girls. At his trial, Lyerla testified that he feared for his life and shot at the truck in order to disable it. Lyerla was acquitted on all charges of first degree murder and attempted first degree murder, but was convicted of second degree murder for killing Jensen and of attempted second degree murder of the other girls. Lyerla appealed his convictions to the Supreme Court of South Dakota.