Due Process and State Choice

Due Process and State Choice

The earlier sections treated the full two-part M'Naghten formulation as the template, which raises the question whether a state that departs from it runs afoul of the Constitution. The Court answered no in Clark v. Arizona, holding that due process does not prohibit a state from stating its insanity test solely in terms of the capacity to tell whether an act charged as a crime was right or wrong.¹ Arizona had first adopted the whole M'Naghten statement, including a cognitive prong (did a mental defect leave the defendant unable to understand what he was doing) and a moral prong (did it leave him unable to understand that his act was wrong), and the legislature later dropped the cognitive prong. Under current Arizona law, a defendant is not adjudged insane unless he shows that, at the time of the crime, a mental disease or defect of such severity left him not knowing that the criminal act was wrong.²

Clark argued that the side-by-side M'Naghten test is the minimum a government must provide, and that eliminating its first part offends a principle of justice so deeply rooted in the traditions and conscience of the people that it ranks as fundamental. A claim of that kind carries a heavy burden, and the Court held that Clark did not carry it.³ The reasoning follows from what the inquiry asks. A rule can be rooted in tradition only if the tradition is reasonably uniform, and the history of insanity law is not. The Court found significant differences among the traditional Anglo-American approaches, with four traditional strains combined in different ways to yield a diversity of American standards: 17 states and the federal government have recognizable versions of the M'Naghten test with both components, while other states use a variety of standards built on all or part of one or more of the four variants, and the prescribed insanity verdicts differ as well.⁴ Counted more loosely, M'Naghten remains the predominant American test, used in the federal courts and more than thirty states, sometimes with slight variations or a volitional supplement, while a substantial minority of states has rejected it, usually in favor of the Model Penal Code approach.⁵ Because no formulation has become a baseline, the insanity rule, like the definition of criminal offenses, is substantially open to state choice, which fits the traditional recognition that states define crimes and defenses.⁶

The range of state choices shows up in individual decisions. In State v. Johnson the Rhode Island Supreme Court reasoned that no exact definition of insanity is possible, that a legal standard must reflect community values while fitting what science understands, and that M'Naghten had been fixed into the common law just as the psychological theories behind it were falling into disrepute, and the court replaced the test with a version of the Model Penal Code standard.⁷ Kansas went further in 1995 and abolished insanity as a separate defense, so that mental disease matters there only to the extent it shows the defendant lacked the mens rea the offense requires.⁸ In Kahler v. Kansas the Court declined to make the moral-incapacity test a constitutional requirement, observing that the test has never been the dominant rule and that a constitutional mandate would invalidate not only Kansas's approach but the laws of many other states.⁹ States also differ over which mental illnesses can support the defense at all, since some limit it to severe disease and others exclude particular disorders.¹⁰ The federal Constitution also probably does not require a state to recognize insanity as a complete defense.¹¹

Clark also complained, more narrowly, that the shortened test shortchanged him of a constitutional minimum by removing the cognitive prong. The Court rejected that complaint because cognitive incapacity remains relevant under the wrongfulness-only formulation. The two prongs are linked: a defendant who did not know what he was doing could not have known that he was performing the wrongful act charged as a crime, so cognitive incapacity is itself enough to show moral incapacity.¹² The Court accepted Clark's point that applying the moral test does not necessarily require evaluating cognitive capacity, but that point does not help him, because evidence bearing on whether he knew the nature and quality of his actions is relevant and admissible under the short form, with the same significance it had under the long form. The record confirmed this, since the trial court admitted his cognitive incapacity evidence for consideration under the moral incapacity formulation, and Clark could point to no evidence bearing on insanity that was excluded.¹³ The shortened test therefore changes the question the jury answers while leaving the evidence it may hear intact.

State freedom over the formulation explains why the earlier sections kept qualifying their rules by reference to the jurisdiction, as with the optional volitional supplement. It also produces two separate exam moves. When a stem asks whether a state's insanity test is unconstitutional because it omits part of M'Naghten, the answer follows Clark and the challenge fails. When a stem asks whether a defendant qualifies as insane, the answer depends on the version the jurisdiction uses, so the analysis applies the formulation the stem supplies and does not import a prong or a supplement it omits. Students lose this issue when they treat the full two-part M'Naghten test as a constitutional minimum and mark a shortened or modified state test as a due process violation.¹⁴