The following is an excerpt from “Abolition of the Insanity Defense Violates Due Process” by Stephen J. Morse, University of Pennsylvania Carey Law School and Richard J. Bonnie, University of Virginia School of Law.
Blame and punishment by the state are fundamentally unfair and thus a violation of the Due Process Clause if an offender was not responsible for his crime. The affirmative defense of legal insanity applies this fundamental principle by excusing those mentally disordered offenders whose disorder deprived them of rational understanding of their conduct at the time of the crime. This principle is simple but profound. Indeed, in recognition of it, the
insanity defense has been a feature of ancient law and of English law since the 14th century. It was universal in the United States until the last decades of the 20th century, and there is still a near consensus among state and federal lawmakers that the defense must be retained.
The concept of responsibility connects with our most fundamental convictions about human nature and dignity and our everyday experience of guilt and innocence and blame and punishment. It also explains our common aversion to the idea that we might simply be like machines responding to neural activities in the brain and our resistance to thinking of all wrongdoing as sickness. Failing to provide an insanity defense confounds the meaning of what it is
to be responsible for one’s actions. It cheapens the idea of being a responsible person by classifying and holding responsible persons intuitively regarded as fundamentally non-responsible.
In both law and morals, the capacity for reason is the primary foundation for responsibility and competence. The precise cognitive deficit a person must exhibit can, of course, vary from context to context. In the criminal justice system, an offender who lacks the capacity to understand the wrongfulness of his actions as the result of severe mental disorder does not deserve full blame and punishment and must be excused in a sufficiently extreme case. Moreover, such offenders cannot be appropriately deterred because the rules of law and morality cannot adequately guide them. Failing to excuse some mentally disordered offenders is inconsistent with both retributive and deterrent theories of just punishment.
A similar baseline principle explains the many competence doctrines employed in the criminal justice process. This Court has long recognized that, at every stage, justice demands that some people with severe mental abnormalities must be treated differently from those without substantial mental impairment, because some impaired defendants are incapable of reason and understanding in a specific context. Competence to stand trial, competence to plead
guilty and to waive counsel, competence to represent oneself and competence to be executed are all examples in which the Constitution requires such special treatment. It is unfair to the defendant and offensive to the dignity of criminal justice to treat people without understanding as if their understanding was unimpaired. Evidence of mental disorder is routinely introduced in all these contexts to determine whether the defendant must be accorded special treatment.
Legally insane offenders are not excused solely because they had a severe mental disorder at the time of the crime. The mental disorder must also impair their ability to understand or appreciate that what
they are doing is wrong or some other functional capacity that a jurisdiction believes is crucial to responsibility. The criminal acts of those found legally insane do not result from bad judgment, insufficient moral sense, bad attitudes, or bad characters, none of
which is an excusing condition. Rather, the crimes of legally insane offenders arise from a lack of understanding produced by severe mental abnormality and thus they do not reflect culpable personal qualities and actions. To convict such people offends the basic sense of justice.
The impact of mental disorder on an offender’s responsibility and competence is recognized throughout criminal law. Even the few jurisdictions that have abolished the insanity defense recognize
that mental disorder affects criminal responsibility because it permits the introduction of evidence of mental disorder to negate the mens rea for the crime charged. As the Supreme Court has recognized,
state infliction of stigmatization and punishment is a severe infringement. The insanity defense is grounded in long-recognized legal and moral principles and on routinely admissible evidence. Even if a defendant formed the charged mens rea, it is unfair to preclude a defendant from claiming and proving that he was not at fault as a result of lack of understanding arising from a severely disordered mind.
Historical practice, the near universal acceptance of the need for an independent affirmative defense of legal insanity and the fundamental unfairness of blaming and punishing legally insane offenders provide the strongest reasons to conclude that fundamental fairness and the Due Process Clause require
an insanity defense. Abolishing this narrowly defined and deeply rooted defense could plausibly be justified only if an alternative legal approach could reach the same just result or if irremediably deep flaws preclude fair and accurate administration of the defense.