My grandfather believed in psychiatry and thought experts would be able to say with certainty whether a criminal act had medical roots. He was disappointed. Psychiatrists for the prosecution and the defense regularly split over whether a defendant's mental illness caused him to commit his crime. In 1972, the D.C. Circuit changed course and my grandfather decried the warring experts. He wanted psychiatrists to go on offering diagnoses and descriptions of mental illness. But he also wanted the jury to understand that no one has a "meaningful answer" to whether a person's craziness causes him to commit a crime. The court should "tell the truth," he wrote, "that the jury, not the experts, must judge the defendant's blameworthiness" and decide simply "whether it would be just to hold the defendant responsible for his action."
Expert testimony, the core of my grandfather's critique, is still giving the courts fits. In his majority opinion, Souter wrote that the two experts in Clark's case "agree that Clark was schizophrenic, but they come to opposite conclusions on whether the mental disease in his particular case left him bereft of cognitive or moral capacity. Evidence of mental disease, then, can easily mislead."
That wouldn't be the case, though, if the psychiatrists had stuck to the facts about which there was medical consensus—Clark's schizophrenia and its attendant symptoms. The experts would testify as they're equipped to. And the jury would have to figure out for itself the ultimate questions of moral blameworthiness and guilt for which there is rarely a single answer. None of this will help Eric Clark. But someday, a court or legislature will try again on the insanity defense and get closer to getting it right.