Judicial Notebook

On June 21, 2000, Officer Jeffrey Moritz of the Flagstaff, Ariz., Police Department pulled over a pickup truck driven by 17-year-old Eric Clark. Clark, who had a documented history of schizophrenia and apparently believed that Flagstaff was inhabited by aliens who were trying to kill him, shot and killed Officer Moritz.

After two years of inpatient treatment to restore competency, Clark, at trial, offered evidence of his mental disorder as pertaining to findings of mental state (mens rea) and sanity. At issue was whether Clark's psychotic disturbance precluded him from forming the requisite intent to commit the act and to appreciate the wrongfulness of his conduct. Psychiatric testimony offered in support of Clark suggested that his delusions may have distorted his perception of reality such that he lacked the capacity to appreciate that the police officer was a human being (and not an alien).

The Arizona Supreme Court's previous decision in State v. Mott (187 Ariz. 536, 931 P. 2d 1046) barred psychiatric testimony that might negate specific intent. Thus, Clark was denied the opportunity to use evidence of mental illness to demonstrate the absence of mens rea. Moreover, absent that opportunity, the burden shifted to Clark to demonstrate that he was "guilty but insane" under Arizona's narrower insanity standard. In 1993, the Arizona legislature dropped the first part of the M'Naghten test (knowing the nature and quality of the act), leaving a defendant eligible for the insanity defense only if he or she "did not know the criminal act was wrong," (Ariz. Rev. Stat. Ann ß13-502[A] [West 2001]). Clark's conviction was subsequently affirmed by the Arizona Court of Appeals.

Amicus brief of psychologists and psychiatrists

The American Psychiatric Association, joined by APA and the American Academy of Psychiatry and the Law, filed a brief in support of Clark arguing that due process rights necessitate the opportunity to introduce evidence that might negate the mental state element of a crime. It was argued that Clark's psychotic delusions may have had direct bearing on his mens rea, which expert evidence could address. The brief maintained that denying consideration of such evidence would exclude relevant and reliable evidence.

The brief further argued, as a matter of substantive due process, that an insanity defense ought to preclude serious criminal punishment for a defendant who, as a result of mental disorder, lacks understanding of the wrongfulness of his conduct. Indeed, it was noted that legal tradition has long relieved of criminal responsibility those who lack the capacity to make rational choices about their behavior.

Clark v. Arizona

The Supreme Court ruled in favor of Arizona, finding that conceptualization of an insanity standard is "open to state choice" (Clark v. Arizona, 126 S. Ct. 2709 [2006]) and that there is no minimum formulation of insanity necessary to satisfy due process. The majority opinion (by Justice Souter), in acceptance of Arizona's abridged M'Naghten standard, noted that "History shows no deference to M'Naghten that could limit its formula to the level of fundamental principle...." The Supreme Court further held that psychiatric testimony relevant to mens rea can be excluded from consideration.

Although the majority opinion seemed to indicate that psychiatric testimony relevant to mental state might confuse the trier of fact, Justice Kennedy, in dissent, observed that barring such testimony may dispossess jurors of the opportunity to "make sense" of claims of mental illness. Moreover, the dissent opined that, "Arizona's rule is problematic because it excludes evidence no matter how credible and material it may be in disproving an element of the offense."

Implications for psychologists

Psychologists have historically played a central role in bringing mental state evidence to the courtroom. The Clark ruling, however, serves to limit testimony concerning mens rea. Thus, states may refuse to give consideration to mental illness evidence in determining whether a defendant had the necessary state of mind to commit the act, and simply consider such evidence with regard to an insanity claim.

Because the Clark opinion noted that psychiatric judgments on questions of mental state "are subject to flux and disagreement," empirical research could help determine the reliability of expert evidence on mental conditions relevant to determinations of culpability. The opinion further suggested that mental state evidence has the power to mislead jurors. Thus, future research might also examine how jurors understand mental illness (including cognitive, moral and volitional capacities), both with and without the presentation of expert evidence.

Further Reading

"Judicial Notebook" is a project of APA's Div. 9 (Society for the Psychological Study of Social Issues).