People v. Berry was an important American murder-in-the-heat-of-passion case that gained widespread attention because of the court's novel approach to finding "adequate provocation" in order to lower a regular murder charge to voluntary manslaughter. Because the lower court had insisted on a more traditional definition of "adequate provocation" in its jury instructions, the California Supreme Court reversed Berry's murder conviction. It did, however, affirm Berry's conviction for assault using deadly force.