Under the provocative act murder doctrine, when defendant personally acts willfully, deliberately, and with premeditation in the attempted murder of the victim who then kills defendant’s accomplice, and the attempted murder is a proximate cause of the death, defendant is liable for first degree murder of his accomplice. Appellants and their accomplice threatened to kill victim Harris during an attempted robbery. Harris fled but was chased by the men and, realizing that his life was in danger, Harris pulled a pocket knife, turned on them, and stabbed the accomplice, Sanchez, to death. Appellants were convicted of attempted first degree murder of Harris and, under the provocative murder act doctrine, first degree murder of Sanchez. After granting review to consider whether the provocative murder act doctrine can support a finding of first degree murder, the Supreme Court observed that a defendant is liable for those unlawful killings proximately caused by his or his accomplice’s acts. If proximate causation is established, the degree of liability will then depend on defendant’s personal criminal intent in the attempted murder. Here, although the trial court did not err in instructing the jury that appellants could be convicted of first degree murder under the provocative act murder doctrine, it did err by failing to provide an instruction that explained that for a defendant to be found guilty of first degree murder under the doctrine, he personally had to have acted willfully, deliberately, and with premeditation when he committed the attempted murder, as opposed to being vicariously liable for his accomplice’s intent. The matter was remanded to the Court of Appeal to consider whether this error was prejudicial.