Clark v. Arizona

PETITIONER: Eric Michael Clark
LOCATION: Board of Immigration Appeals

DOCKET NO.: 05-5966
DECIDED BY: Roberts Court (2006-2009)
LOWER COURT: Arizona Supreme Court

CITATION: 548 US 735 (2006)
GRANTED: Dec 05, 2005
ARGUED: Apr 19, 2006
DECIDED: Jun 29, 2006

David I. Goldberg - argued the cause for Petitioner
Paul D. Clement - argued the cause for Respondent
Randall M. Howe - argued the cause for Respondent

Facts of the case

Eric Clark shot and killed a police officer during a traffic stop. At trial in Arizona state court, Clark, a diagnosed paranoid schizophrenic who believed his town had been taken over by aliens, introduced expert evidence about his mental state. He wanted to use this evidence not only to prove that he was insane (a claim on which he bore the burden of proof) but also to show that he could not form the criminal intent that the government was required to prove beyond a reasonable doubt. The trial judge, however, ruled that Arizona law confined the use of the expert evidence to his insanity claim and did not permit him to use it to show he could not form the necessary criminal intent. The court ruled that he had not sufficiently proved his insanity defense, and Clark was convicted and sentenced to 25 years to life in prison. The Arizona Court of Appeals affirmed.


Does a defendant have a Fourteenth Amendment due process right, separate from his insanity plea, to present expert evidence about his mental state to counter the prosecution's evidence of criminal intent?

Media for Clark v. Arizona

Audio Transcription for Oral Argument - April 19, 2006 in Clark v. Arizona

Audio Transcription for Opinion Announcement - June 29, 2006 in Clark v. Arizona

John G. Roberts, Jr.:

Justice Souter has the opinion in 05-5966, Clark v. Arizona.

David H. Souter:

This case comes to us on Writ on Certiorari to the Court of Appeals of Arizona.

Eric Clark was charged with first degree murder under an Arizona Statute prohibiting intentionally or knowingly killing a police officer in the line of duty.

At a bench trial, the prosecutor offered circumstantial evidence of the mental element of the crime, what lawyers called the mens rea, which in this case was that Clark must have known that the victim was a police officer and had intended to kill him.

Clark aimed to rebut this evidence by relying on his undisputed paranoid schizophrenia at the time of the killing.

Clark also raised the defense of insanity requiring him to prove that at the time of the crime he was afflicted with a mental disease or defect of such severity that he did not know that the criminal act was wrong.

The Trial Court ruled that Clark could not rely on evidence bearing on insanity to dispute the mens rea, citing a Supreme Court of Arizona decision in a case called State v. Mott.

As to his insanity then, Clark presented testimony describing his bizarre behavior and beliefs, and psychiatrists for both sides agree that Clark was schizophrenic.

Clark’s expert however, concluded that the schizophrenia kept Clark from appreciating the wrongfulness of killing the officer, while the prosecutor’s expert disagreed.

The judge found Clark guilty of first degree murder and also found that he had not established insanity.

The judge rejected Clark’s arguments that Arizona’s Insanity Test and its Mott rule, each violate due process.

The Court of Appeals of Arizona affirmed; in an opinion filed today with the clerk of the Court we affirm.

Until 1993, Arizona’s Insanity Rule said that a person could be insane on either of two grounds; if mental disease or a defect left him unable to understand what he was doing, that is, if he suffered a cognitive incapacity, or if mental disease or a defect left him unable to understand that his action was wrong, that is, that he suffered a moral incapacity.

Then Arizona amended its law by dropping the Cognitive Incapacity part.

We hold that eliminating the Cognitive Incapacity part does not violate due process by offending any principle of justice so rooted in our traditions as to be fundamental.

The varied background of the insanity defense makes clear that no particular formulation has evolved into a baseline for due process, and the Insanity Rule is substantially open to state choice.

Moreover, Cognitive Incapacity remains relevant under Arizona’s abbreviated rule because the defendant who did not know what he was doing when he acted could not have known that he was performing the wrongful act, charged as a crime.

We also hold that the Mott Rule does not offend due process.

As to mens rea, Mott restricts consideration of certain mental disease and mental capacity evidence, evidence that typically comes as a professional psychiatrist’s opinion saying whether a defendant has suffered from a mental disease, and if he has, whether the disease has left him incapable of cognition or moral judgment.

The Arizona Mott rule says that this kind of typically psychiatric testimony may be considered only on the question whether the defendant was insane, not on the question of what was actually in his mind when he committed the act he was charged with.

We think this is constitutional; the Constitution prohibits the exclusion of defense evidence under rules that serve no legitimate purpose or that are disproportionate to the ends that they are claimed to promote.

Nonetheless, trial judges can limit evidence if its prohibitive value is outweighed by a risk of confusing the issues or by a potential to mislead the jury.

By this measure, we hold that the Mott Rule satisfied due process.

First, Arizona has authority to define its presumption of sanity by choosing an insanity definition that places the burden of persuasion on defendants claiming insanity as a defense.

Arizona must then be able to deny a defendant the opportunity to displace the sanity presumption more easily when addressing a different issue, mens rea, which the prosecution must prove beyond a reasonable doubt.

Second, Arizona’s rule serves to avoid jury confusion and misunderstanding arising from the controversial character of some categories of mental disease, from the potential of mental disease evidence to mislead, and from the danger of according greater certainty to capacity evidence than experts can claim for it.

For these reasons, we hold that there is also no cause to claim that channeling evidence on mental disease and capacity to the insanity issue offends the principle of justice so rooted in our traditions as to be fundamental.

Justice Breyer has filed an opinion concurring in part and dissenting in part; Justice Kennedy has filed a dissenting opinion in which Justices Stevens and Ginsburg join.