In what circumstances will a defendant be convicted of first degree murder for a hammer attack?

In People v. Anderson, supra, 70 Cal.2d 15, 73 Cal.Rptr. 550, 447 P.2d 942, the defendant lived with the family of the 10-year-old victim. He killed the victim in a brutal assault involving over 60 knife wounds all over the child's body. Although there was no question that defendant was the perpetrator, there were no eyewitnesses to the crime and there was no explanation of what led up to the murder. The defendant did not testify or confess. There was, however, evidence of the defendant's subsequent efforts to conceal the crime. On this record, our court concluded that the evidence was insufficient to demonstrate that the murder was premeditated or deliberate. We therefore reduced the conviction from first to second degree murder.

In People v. Wharton, supra, 53 Cal.3d 522, 280 Cal.Rptr. 631, 809 P.2d 290, the defendant killed the woman with whom he had been living, stuffed her body in a barrel, and left it in the apartment. The autopsy revealed that the victim had been struck three times on the head with a blunt instrument, probably a hammer. A hammer was found hidden under a mattress, and the hammer was missing from a toolbox kept in the garage. The defendant confessed, claiming that he had killed the victim in an uncontrolled rage. On appeal, we found the evidence sufficient to support the jury's finding of premeditation and deliberation. The evidence indicated that the defendant either retrieved the hammer in advance to have it accessible in the event of an argument, or that the defendant became angry during the argument and went to the garage to obtain the hammer and kill the victim while she slept. Either version was sufficient to support planning activity. We also identified a plausible motive--the defendant was selling some of the victim's belongings. Though admitting that these were not the only inferences that could be drawn, we found the evidence of planning and motive sufficient despite the fact that the manner of killing was not in itself indicative of a preconceived design to kill. (Id. at p. 548, 280 Cal.Rptr. 631, 809 P.2d 290.)