WASHINGTON — In the first argument of its new term, the Supreme Court on Monday considered whether states may abolish the insanity defense, a question that seemed to puzzle several of the justices, who drew conflicting lessons from history, moral philosophy, constitutional law and the brutal crimes at the heart of the case.
James Kahler of Kansas was sentenced to death in 2011 for killing four family members, but his lawyers said he had severe depression that made it impossible for him to understand reality or to distinguish right from wrong.
Kansas eliminated the insanity defense about two decades ago, so he was barred from raising the defense that he had been mentally ill. Sarah Schrup, a lawyer for Mr. Kahler, said that was a radical departure from American legal traditions.
“For centuries,” she said, “criminal culpability has hinged on the capacity for moral judgment, to discern and to choose between right and wrong. The insane lack that capacity.”
Idaho, Montana and Utah have also abolished the insanity defense, meaning that defendants in those states cannot avoid criminal punishment by showing that their mental illness prevented them from knowing their actions were wrong. Instead, defendants may argue that they lacked the required intent to commit the crime with which they were charged.
The distinction matters, Justice Stephen G. Breyer said, using examples. In Kansas, he said, defendants are not culpable if they do not know what they were doing (by, for instance, killing a human being under the delusion that they are killing a dog). But they are culpable, he said, if they do not know that their actions are wrong (by, for instance, believing a dog instructed them to kill a human being).
“The first defendant thinks that Smith is a dog,” Justice Breyer said, referring to a hypothetical victim. “The second defendant knows it’s a person but thinks the dog told him to do it. O.K.? What’s the difference?”
Toby Crouse, Kansas’ solicitor general, said states should be allowed to make their own judgments in defining responsibility for crimes.
Justice Samuel A. Alito Jr. said Mr. Kahler’s actions did not appear to be those of an insane person.
“This is an intelligent man,” Justice Alito said, “and he sneaked up on the house, where his wife and her mother and his children were staying. He killed his ex-wife. He killed her mother. He executed his two teenage daughters. One of them is heard on the tape crying. He, nevertheless, shot her to death.”
“Now, this is the stuff from which you’re going to make a defense he didn’t know that what he was doing was morally wrong, much less he didn’t know what he was doing was legally wrong?” Justice Alito asked Ms. Schrup.
She responded that Mr. Kahler’s lawyers should have been allowed the opportunity to argue that he was insane. “The facts are hard in every case, and they are hard in this case,” Ms. Schrup said. “But what we’re talking about is an opportunity, a mechanism for all defendants, to be able to get into the threshold and let a jury decide.”
Before the argument began, Chief Justice John G. Roberts Jr. announced that Justice Clarence Thomas was “indisposed due to illness,” and would participate in the day’s arguments based on briefs and transcripts. A court spokeswoman said Justice Thomas was resting at home and appeared to have the flu.
Justice Ruth Bader Ginsburg, who had missed two weeks of arguments in January after cancer surgery, asked the first question. It came later than usual, as the justices, thanks to a new practice announced last week, will now generally allow lawyers to speak for two minutes before peppering them with questions.
The argument ended without apparent consensus. Justice Breyer mused that the issue the court would decide in the case, Kahler v. Kansas, No. 18-6135, was a profound one. “It’s quite deep, this question,” he said.