Fifth Amendment:
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
It is a denial of due process to try or sentence a defendant who is insane
or incompetent to stand trial.1 When it becomes evident during the trial that a defendant is or has become insane
or incompetent to stand trial, the court on its own initiative must conduct a hearing on the issue.2 Although there is no constitutional requirement that the state assume the burden of proving a defendant competent, the state must provide the defendant with a chance to prove that he is incompetent to stand trial. Thus, a statutory presumption that a criminal defendant is competent to stand trial or a requirement that the defendant bear the burden of proving incompetence by a preponderance of the evidence does not violate due process.3
When a state determines that a person charged with a criminal offense is incompetent to stand trial, he cannot be committed indefinitely for that reason. The court’s power is to commit him to a period no longer than is necessary to determine whether there is a substantial probability that he will attain his capacity in the foreseeable future. If it is determined that he will not, then the state must either release the defendant or institute the customary civil commitment proceeding that would be required to commit any other citizen.4
Where a defendant is found competent to stand trial, a state appears to have significant discretion in how it takes account of mental illness or defect at the time of the offense in determining criminal responsibility.5 The Court has identified several tests that are used by states in varying combinations to address the issue: the M'Naghten test (cognitive incapacity or moral incapacity),6 volitional incapacity,7 and the irresistible-impulse test.8 [I]t is clear that no particular formulation has evolved into a baseline for due process, and that the insanity rule, like the conceptualization of criminal offenses, is substantially open to state choice.
9 For example, in Kahler v. Kansas, the Court held that the Due Process Clause does not require a state to adopt M'Naghten's moral-incapacity test as a complete insanity defense resulting in an acquittal.10 The Court stated that [d]efining the precise relationship between criminal culpability and mental illness,
because it involves hard choices
among competing values and evolving understandings of mental health, is a project for state governance, not constitutional law.
11
Commitment to a mental hospital of a criminal defendant acquitted by reason of insanity does not offend due process, and the period of confinement may extend beyond the period for which the person could have been sentenced if convicted.12 The purpose of the confinement is not punishment, but treatment, and the Court explained that the length of a possible criminal sentence therefore is irrelevant to the purposes of . . . commitment.
13 Thus, the insanity-defense acquittee may be confined for treatment until such time as he has regained his sanity or is no longer a danger to himself or society.
14 It follows, however, that a state may not indefinitely confine an insanity-defense acquittee who is no longer mentally ill but who has an untreatable personality disorder that may lead to criminal conduct.15
In Atkins v. Virginia, the Court held that the Eighth Amendment also prohibits the state from executing certain persons with an intellectual disability, and added, [W]e leave to the State[s] the task of developing appropriate ways to enforce the constitutional restriction upon [their] execution of sentences.
16
Issues of substantive due process may arise if the government seeks to compel the medication of a person found to be incompetent to stand trial. In Washington v. Harper,17 the Court had found that an individual has a significant liberty interest
in avoiding the unwanted administration of antipsychotic drugs. In Sell v. United States,18 the Court found that this liberty interest could in rare
instances be outweighed by the government's interest in bringing an incompetent individual to trial. First, however, the government must engage in a fact-specific inquiry as to whether this interest is important in a particular case.19 Second, the court must find that the treatment is likely to render the defendant competent to stand trial without resulting in side effects that will interfere with the defendant's ability to assist counsel. Third, the court must find that less intrusive treatments are unlikely to achieve substantially the same results. Finally, the court must conclude that administration of the drugs is in the patient's best medical interests.