Jurisprudence

The Supreme Court Let States Kill the Insanity Defense

So why does Justice Elena Kagan’s majority opinion pretend otherwise?

Gorsuch speaks to Kagan, both wearing their robes
Justice Elena Kagan with Justice Neil Gorsuch before the State of the Union address at the U.S. Capitol on Feb. 4.
Brendan Smialowski/Getty Images

On Monday, the Supreme Court dealt a death blow to the insanity defense. Justice Elena Kagan joined the five Republican-appointed justices in Kahler v. Kansas to uphold a murder conviction and death sentence for James Kahler, who killed his estranged wife and her family. He wanted to argue at trial that he was not guilty of the murder charges because severe mental illness kept him from thinking or acting rationally at the time. But in 1995, Kansas had changed its criminal law in a way that prevented Kahler from raising the insanity defense.

There is no universal test for the insanity defense, but in many states, a defendant who suffers from a mental illness must be acquitted if, at the time she committed her crime, she either did not know what she was doing or she did not know that what she was doing was wrong. A handful of states have abolished the defense. In those states, mentally ill people who commit crimes may be convicted even if they had no control or understanding of their actions at the time.

In his petition to the Supreme Court, Kahler asked whether the due process clause allows states to “abolish the insanity defense.” This is a tricky argument to make. Most due process arguments are about process, but Kahler’s argument was about substance—it sought limits on a state’s ability to define crimes. The Supreme Court has previously said that a state law about crimes and defenses can violate due process only if it “offends some principle of justice so rooted in the traditions and conscience of our people as to be ranked as fundamental.” In other words, the test is whether the state rule conflicts with another rule that is so old and so important that it is incompatible with the basic idea of “due process of law.”

Most criminal law rules probably aren’t old enough or important enough to be called “fundamental.” But the insanity defense is that old and important. In fact, the majority opinion in Kahler seems to admit as much, saying “Kahler is right that for hundreds of years jurists and judges have recognized insanity (however defined) as relieving responsibility for a crime.” Indeed, the majority opinion said that the court did not find “a single case” that did not recognize the insanity defense.

So how did the court uphold Kahler’s conviction? Kagan’s majority opinion said that Kansas did not abolish the insanity defense; it merely changed the defense. That is not true.

The majority relied on two aspects of Kansas law to support its claim that Kansas has not abolished the insanity defense: laws that identify mental illness as a mitigating sentencing factor and a law that says it is “a defense to a prosecution” that “the defendant, as a result of mental disease or defect, lacked the culpable mental state required” for a crime. Both laws address the issue of mental illness. But neither is an insanity defense.

First, let’s talk about sentencing. Kansas, like most other states, identifies aggravating and mitigating sentencing factors. Those factors tell judges and juries what sort of facts and circumstances they should consider in deciding whether to impose a higher sentence or a lower sentence. One of the mitigating factors that Kansas identifies is mental illness. But that hardly means insanity is a defense. Defenses are about blocking convictions; sentencing factors just set punishment after a conviction.

If a jury believes the defendant has proven a defense, then it must acquit that defendant. In contrast, a mitigating sentencing factor doesn’t result in an acquittal; the defendant is still convicted of the crime. A mitigating sentencing factor doesn’t even guarantee a shorter sentence. It is just one of many facts and circumstances that the judge or jury can consider in deciding what sentence the defendant will receive. A mitigating sentencing factor is completely different from a defense to a crime. They are so different that I cannot understand why the majority even included this idea in the opinion.

I do, however, understand why the majority discussed the other Kansas law—after all, the law itself says that mental illness is “a defense to a prosecution.” But if we dig deeper, this law doesn’t actually give any rights to defendants. It just restates the burden that prosecutors always have: to prove that the defendant acted with whatever mental state is included as an element of the crime.

Here’s an example to illustrate the difference. Imagine two defendants who are charged with murder—the intentional killing of another person. The first defendant says he killed his victim, but he did so in self-defense. The second defendant says that she accidentally shot the victim while cleaning a firearm and that she didn’t intend to kill her. The first defendant has raised what we call an “affirmative defense,” but the second victim has not. Instead, the second defendant is challenging the prosecutor’s case: She is saying that she didn’t commit the crime because she killed the victim accidentally, not intentionally.

The second defendant does not need a state law that allows her to raise a “defense” of accidental shooting. Defendants always have the ability to challenge a prosecutor’s case, and prosecutors always bear the burden of proving each element of a crime beyond a reasonable doubt. The second defendant shows that Kansas’ “insanity defense” is not actually a defense at all. Even if that law didn’t exist, defendants would still be able to avoid conviction for any crime if they don’t have the “mental state required” for that crime. That’s basic criminal law, not the insanity defense.

In adopting this emaciated role for mental illness, Kansas has abolished anything that might accurately be called an “insanity defense.” All it retains is the idea that prosecutors must bear the burden of proving each element of a crime beyond a reasonable doubt. But we shouldn’t give Kansas credit for retaining that burden. The Supreme Court decided decades ago that the burden of proof beyond a reasonable doubt is a principle so “fundamental” that it is guaranteed by the due process clause. Kansas doesn’t give mentally ill defendants anything that they weren’t already guaranteed under the Constitution.

Why does it matter that the Kahler majority refused to characterize what Kansas did as abolishing the insanity defense? For one thing, this sleight of hand is what made Kahler lose this case. By saying that Kansas had changed its insanity defense (rather than abolishing it), the majority was also able to say Kahler was really just arguing in favor of a particular type of insanity defense rule. Then the majority (over objections raised in the dissent) concluded that there was not enough historical evidence in favor of that particular insanity defense rule to give it special status under the due process clause.

While explaining that there is no single formulation of the insanity defense rule that garnered a “settled consensus,” the court declared: “No insanity rule in this country’s heritage or history was ever so settled as to tie a State’s hands centuries later.” Perhaps the court meant only to state that states are free to experiment with their own insanity defense rules. But given what the majority upheld in Kansas, we now know that those experiments can include a “defense” that, in reality, provides no protection at all.