The technical legal question the Supreme Court will address in Kahler v. Kansas is whether the Eighth and Fourteenth Amendments permit a state to abolish the insanity defense. In more colloquial terms, the question is whether states may abolish a defense to criminal liability that mental illness prevented a defendant from knowing his or her actions were wrong. Five state have done so—Alaska, Idaho, Kansas, Montana, and Utah.
James Kahler was sentenced to death for fatally shooting his wife, her grandmother, and his two daughters. Kahler presented the testimony of a forensic psychiatrist who stated that Kahler was suffering from severe major depression at the time of the crime and that “his capacity to manage his own behavior had been severely degraded so that he couldn't refrain from doing what he did.”