In sanity trial, the jury should have been instructed that the defendant was legally insane if (1) he suffered from a delusional state and (2) his delusion, if true, would lawfully justify killing in self-defense. Leeds, a paranoid schizophrenic, killed his father and three other men because he believed they were conspiring to kill him. Pursuant to a plea agreement that precluded imposition of a death sentence, he entered pleas of guilty and not guilty by reason of insanity to four counts of first degree murder, and admitted other allegations. At his sanity trial, defense experts testified that Leeds was legally insane when he killed because he acted under delusions; the prosecution challenged these opinions. The jury was instructed that Leeds was insane if, because of mental disease or defect, he was incapable of knowing or understanding the nature and quality of his act or understanding that his act was morally or legally wrong. (See CALCRIM No. 3450.) Over defense objection, the court instructed the jury that the concept of “morally and legally wrong” refers to society’s generally accepted standards and not Leeds’ subjective belief. Leeds was found sane on all counts. On appeal he challenged the jury instructions. Held: Reversed in part. A person is legally insane at the time of a crime if he suffered from a mental disease or defect that caused him to actually believe that he was in imminent danger of being killed or suffering great bodily injury and that imminent use of deadly force was necessary to defend against the danger. “Without applying the facts as Leeds perceived them to the law of self-defense, the jury would have no way of evaluating whether his paranoid schizophrenia rendered him incapable of appreciating the wrongfulness of his actions.” The error was prejudicial as to his father’s killing because Leeds thought his father had a gun and was about to kill him. As to the other three men, the error was harmless because there was no evidence Leeds perceived he was in imminent danger when he killed them.