Evelonia Hunter and Duane Spann were drinking and smoking crack cocaine in the motel room where Hunter lived. Hunter and Spann encountered Hunter’s former boyfriend, Steve Vickers, and his friend Julius Cox (defendant) outside the motel. Hunter and Vickers began arguing. Vickers spat in Hunter’s face and slapped Spann across the face. Cox then punched Spann once in the head, and Spann fell, unconscious. Vickers and Cox left. Hunter roused Spann and helped him back to the motel room. Spann’s speech was slurred and slow, but he went to sleep after telling Hunter he did not want to call for help. Spann died later that evening from a fractured skull. Cox was charged with involuntary manslaughter, and under the misdemeanor-manslaughter doctrine, the jury was instructed that the underlying battery was a sufficiently dangerous misdemeanor that no further proof of the circumstances was required. Cox was convicted and the court of appeal affirmed the conviction upon Cox’s appeal. The Supreme Court of California granted review.