James Kraig Kahler intentionally shot and killed his wife, their two teenage daughters and Mrs. Kahler’s grandmother in 2009. Now he’s going to the Supreme Court. At his Kansas trial, the defense psychiatrist testified that Mr. Kahler had lost touch with reality due to a serious mental disorder. But the defendant couldn’t offer an insanity defense, because Kansas passed a law abolishing it in 1995. Some form of an insanity defense has been part of English law since the late Middle Ages.