Also known as:mental disease evidence · evidence of mental disease · mental illness evidence
Written by attorneys — see sources below.
A category of expert opinion testimony in criminal cases describing a defendant's diagnosed mental disease or defect and its characteristic features. The testimony is typically offered by psychologists or psychiatrists to support an insanity defense or to show that the defendant lacked the mental state required for the charged offense.
See Our Sources
How its tested
Common Examples
2
Untimely Notice Bars Expert Testimony
Malcolm McKinley pleaded not guilty to arson charges. Six weeks later, after the omnibus deadline, his counsel filed a written notice announcing an intent to rely on a mental disease defense. The prosecutor moved to exclude the psychiatrist's testimony that McKinley suffered from untreated schizophrenia at the time of the fire. The court granted the motion because the notice was filed outside the ten-day window and McKinley failed to show good cause for the delay.
Expert Testimony Limited to Insanity Claim
Melanie Morris was charged with murder after shooting a police officer. She sought to introduce psychiatric testimony that she suffered from paranoid schizophrenia with delusions that government agents were aliens. The trial court permitted the evidence only on the insanity defense and instructed the jury it could not consider the testimony when deciding whether Morris formed the intent to kill. The restriction prevented the jury from using the diagnosis to negate mens rea.
Clark v. Arizona548 U.S. 735, 752 n.20, 126 S.Ct. 2709, 165 L.Ed.2d 842 (2006)
In the early hours of June 21, 2000, Officer Jeffrey Moritz of the Flagstaff Police responded in uniform to complaints that a pickup truck with loud music blaring was circling a residential block.
When he located the truck, the officer turned on the emergency lights and siren of his marked patrol car. This prompted petitioner Eric Clark, the truck’s driver (then 17), to pull over.
Officer Moritz got out of the patrol car and told Clark to stay where he was. Less than a minute later, Clark shot the officer. The officer died soon after but not before calling the police dispatcher for help. Clark ran away on foot but was arrested later that day with gunpowder residue on his hands. The gun that killed the officer was found nearby, stuffed into a knit cap.
Clark was charged with first-degree murder under Ariz. Rev. Stat. Ann. §13–1105(A)(3) for intentionally or knowingly killing a law enforcement officer in the line of duty. In March 2001, Clark was found incompetent to stand trial and was committed to a state hospital for treatment. Two years later the same trial court found his competence restored and ordered him to be tried. Clark waived his right to a jury, and the case was heard by the court.
At trial, Clark did not contest that he shot the officer or that the officer died. He relied on his own undisputed paranoid schizophrenia at the time of the incident to deny that he had the specific intent to shoot an officer or knowledge that he was doing so. The prosecutor offered circumstantial evidence that Clark knew the victim was a police officer. The prosecutor also offered testimony indicating that Clark had previously stated he wanted to shoot police and had lured the victim to the scene to kill him.
In presenting the defense case, Clark claimed mental illness. He sought to introduce it for two purposes. First, he raised the affirmative defense of insanity. This put the burden on himself to prove by clear and convincing evidence that at the time of the crime he was afflicted with a mental disease or defect of such severity that he did not know the criminal act was wrong. Second, he aimed to rebut the prosecution’s evidence of the requisite mens rea.
Ruling that Clark could not rely on evidence bearing on insanity to dispute the mens rea, the trial court cited the Arizona Supreme Court’s decision in State v. Mott. That decision refused to allow psychiatric testimony to negate specific intent. It held that Arizona does not allow evidence of a mental disorder short of insanity to negate the mens rea element of a crime. As to his insanity, Clark presented lay testimony describing his increasingly bizarre behavior over the year before the shooting. This included testimony that Clark thought Flagstaff was populated with aliens trying to kill him and that bullets were the only way to stop them.
A psychiatrist testified that Clark was suffering from paranoid schizophrenia with delusions about aliens when he killed the officer. The psychiatrist concluded that Clark was incapable of luring the officer or understanding right from wrong and was thus insane at the time of the killing. In rebuttal, the State’s psychiatrist gave his opinion that Clark’s paranoid schizophrenia did not keep him from appreciating the wrongfulness of his conduct before and after the shooting.
The judge then issued a first-degree murder verdict. The judge found that Clark had not established that his schizophrenia distorted his perception of reality so severely that he did not know his actions were wrong. Clark moved to vacate the judgment and life sentence. He argued that Arizona’s insanity test and its Mott rule each violate due process. The trial court denied the motion. Affirming, the Arizona Court of Appeals held that the State’s insanity scheme was consistent with due process. The court read Mott as barring the trial court’s consideration of evidence of Clark’s mental illness and capacity directly on the element of mens rea. The Supreme Court of Arizona denied further review. The United States Supreme Court granted certiorari.
What procedural step must a defendant complete before mental-disease evidence is admissible?
The defendant must file a written notice of intent to rely on a mental disease or defect defense at the time of the not guilty plea or within ten days thereafter. Late notice is permitted only upon a showing of good cause. Without timely notice the evidence is inadmissible.
Does a change in psychiatric diagnosis after the initial notice invalidate the notice?
No. The notice requirement is satisfied by a timely written declaration of intent to rely on the defense. The statute does not require a formal diagnosis at the time of filing or a renewed notice when the precise diagnosis later shifts.
May mental-disease evidence be considered on the issue of mens rea in every jurisdiction?
No. Some jurisdictions restrict mental-disease evidence to the insanity defense and prohibit its use to negate mens rea. The evidence may be admitted only for the limited purpose of showing lack of criminal responsibility.
What showing permits a court to accept an untimely notice of a mental-disease defense?
The defendant must demonstrate good cause for the delay, such as a recently discovered condition that could not reasonably have been identified earlier. The court then has discretion to permit the late filing.
548 U.S. 735, 126 S. Ct. 2709, 165 L. Ed. 2d 842 (2006)
…or capacity presumption may be placed in issue. First, a State may allow a defendant to introduce (and a factfinder to consider) evidence of mental disease or incapacity for the bearing it can have on the government’s burden to show mens rea . Second, the sanity presumption’s force may be tested in the consideration of an insanity defense…