The court accepted the case of Kansas death-row inmate James Kraig Kahler, who was convicted of killing four family members in 2009. The cert petition argues Kansas can’t curtail the insanity defense under the Eighth Amendment’s ban on cruel and unusual punishment and the 14th Amendment’s due process clause.
The Kansas insanity law, adopted in 1996, provides that mental disease or defect is not a defense unless it negates a required element of the crime, such as intent to commit murder. Under the 1996 law, inability to know right from wrong is not a defense to a crime, the cert petition says.
“Even a capital murder defendant need not be of sound mind” to be convicted, the petition says. “So long as he knowingly killed a human being—even if he did it because he believed the devil told him to, or because a delusion convinced him that his victim was trying to kill him, or because he lacked the ability to control his actions—he is guilty.”
Kahler was so depressed at the time of the crime that he was disassociated from reality, according to the cert petition. “Although he knew that he was shooting at human beings,” the cert petition says, “his mental state was so disturbed at the time that he was unable to control his actions.”
Kansas is one of five states that do not permit a defendant to assert as a defense that mental illness prevented him from knowing his actions were wrong, according to the cert petition. The other states are Alaska, Idaho, Montana, and Utah.
Before Kansas adopted its current insanity rule in 1996, it had applied the more liberal M’Naghten rule. It provides that a defendant is not criminally responsible if he does not know right from wrong, or if he doesn’t know the nature and quality of his act.
SCOTUSblog notes the cert grant and links to the cert petition, while the Topeka Capital-Journal has February 2018 coverage of the Kansas Supreme Court decision upholding Kahler’s conviction.