Also known as: product of mental illness test · product test · Durham test · Durham rule
Written by attorneys — see sources below.
A causation-based insanity standard that acquits a defendant when the charged offense resulted from a mental disease or defect. The test requires but-for causation between the mental condition and the criminal act.
Priya Prasad, an emergency room nurse, attacked a pharmaceutical representative with trauma shears while experiencing severe postpartum psychosis. Defense experts testified that but for the psychosis and its accompanying delusion that the representative was poisoning patients, Priya would not have committed the assault. The jury acquitted her because the offense was the product of her mental disease.
Perry Pratt, a nuclear plant technician with a documented schizo-paranoid disorder, bypassed three redundant safety interlocks while experiencing fixed delusions that federal agents had installed hidden shutdown mechanisms. He immediately told investigators he acted solely to thwart the conspiracy. The court granted acquittal because the conduct resulted from his mental disease.
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.
View caseThe product test focuses solely on whether the offense resulted from a mental disease or defect through but-for causation. It does not require proof that the defendant lacked capacity to know right from wrong or to control conduct.
Supporting sources
Expert testimony linking the mental disease directly to the criminal act satisfies the requirement when the evidence shows the defendant would not have committed the offense absent the condition. Courts examine motive, timing, and the relationship between the diagnosed condition and the specific actions taken.
Supporting sources
Yes. When evidence shows the defendant would have committed the offense even without the mental disease, such as prior identical conduct driven by production quotas, the but-for link is broken and acquittal is not required.
Supporting sources
Such evidence may support a finding that the conduct was not solely the product of mental disease. When the defendant selects a remote location and times the act to minimize detection, a court may conclude the offense reflected intentional conduct rather than the mental condition alone.
Supporting sources
…a person was so lacking in volition due to a mental defect or illness that he could not have controlled his actions. And the product-of-mental-illness test was used as early as 1870, and simply asks whether a person’s action was a product of a mental disease or defect. Seventeen States and the Federal Government have adopted…