Marjorie Diehl clearly was mentally ill, but the degree of her imbalance represented the critical issue before and during her trial for killing Bob Thomas. Though undeniably troubled, Diehl ultimately was found not to be insane or so mentally unfit as to be unable to understand the court proceedings and assist in her defense. The Thomas case, like those that would follow for Diehl-Armstrong, including the Pizza Bomber prosecution, illustrated the interplay between insanity and mental incompetency—two categories central to the American legal system’s handling of the mentally ill.
The Diagnostic and Statistical Manual of Mental Disorders, for all its heft, has no entry for insanity as a disorder. Insanity, as understood today, is not a psychiatric illness but a construct, “a legal term.”1 No longer is “insane” the category that applies to all the mentally ill; Emil Kraepelin ended that sweeping generalization in 1899 when he divided most mental illness into the two main categories: schizophrenia and manic-depression, or bipolar disorder. Rather than being a form of mental illness, insanity today represents mental illness with a legal and moral component; insanity, according to its most basic legal definition, means that a defendant is so mentally ill as to be unable to understand right from wrong at the time he or she committed a crime. The concepts of insanity and mental competency reside close to the core of English common law and American jurisprudence, with their emphasis on good and evil and free will. Through the insanity defense and mental incompetency, the law recognizes that a criminal defendant can be so mentally disturbed as to lack the ability to choose his or her actions. The continued existence of insanity and mental competency as legal constructs, despite their critics, indicates how the social sciences and empiricism have come to modify the justice system and its belief that choice, to varying degrees, is behind human criminal behavior.2
Criminal cases involving insanity and mental incompetency can be among the most highly publicized, particularly when they include murder. One study has found that 7.5 percent of crimes committed by those with serious mental disorders “were directly related to symptoms of mental illness.”3 The same study also found that “14%–16% of the 7.3 million people under correctional supervision [as of 2009] suffer from serious disorders such as schizophrenia, bipolar disorder, or major depression. This translates to approximately one million people with a major mental disorder currently involved in the criminal justice system.”4
A temporal element differentiates the concepts of mental incompetence and insanity. The insanity defense applies to the defendant’s state of mind when he or she committed a crime. Determining whether a defendant is mentally competent to stand trial focuses on his or her mental state at the time of prosecution: whether the defendant understands the legal process, and whether—as was the critical issue in Diehl’s case—the defendant is able to assist the defense at trial. The concepts of legal insanity and mental incompetence recognize that a civilized society must take special precautions in criminal cases involving mentally ill defendants, though the concepts also recognize that mental illness alone does not automatically exempt a defendant from prosecution. The severity of the mental illness is the prime consideration in applying both concepts.
The concept of mental competency is the younger of the two. It is believed to have originated in the fourteenth century, when, as scholars Patricia E. Erickson and Steven E. Erickson have written, the English courts proceeded with a criminal trial only after a defendant pleaded “guilty” or “not guilty.” A defendant who “stood mute” and entered no plea prompted an investigation into whether that person was faking mental illness, and thus was “mute of malice”; or was “mute by visitation of God”—truly suffering from muteness, deafness, or mental illness severe enough to be excused from trial.5 By the eighteenth century, the preeminent English legal authority Sir William Blackstone explained how the courts must deal with a defendant who is incompetent to stand trial:
If a man in his sound memory commits a capital offense, and before his arraignment for it, he becomes mad, he ought not be arraigned for it; because he is not able to plead to it with that advice and caution that he ought. And, after he has pleaded, the prisoner becomes mad, he shall not be tried; for how can he make is defence?6
The basics of Blackstone’s common law definition of competency eventually became incorporated in criminal law in the United States. The Supreme Court, in the 1960 decision Dusky v. United States, ruled that a mentally ill defendant, to be found competent to stand trial, must have “sufficient present ability to consult with a lawyer with a reasonable degree of rational understanding” and must have a “rational as well as factual understanding of the proceedings against him.”7 The Dusky decision emphasized that whether a defendant could reasonably assist in his or her defense was the benchmark for legal competency, rather than whether the defendant simply had a clear understanding and recollection of the facts of the case.8
Later rulings refined the definition of mental competency, and set the standard for how a defendant could be restored to competency, after years of psychiatric treatment, as Marjorie Diehl was in the Thomas case. The rulings also established how often a judge must evaluate whether an incompetent defendant has been restored to competency. Once deemed competent, a mentally unstable defendant is not precluded from arguing that he or she was insane at the time of the crime, and thus not responsible for it.
As with madness, the idea that mental illness and insanity could excuse or explain criminal behavior was known to the ancient Greeks and Romans; as one historian has noted, the origins of the concept of legal insanity are “hidden in the mists of the Bosphorus,” referring to the Byzantine Empire’s landmark waterway, in modern Turkey, that separates Europe and Asia.9 Ancient Jewish and Islamic law defined insanity and declared that an insane person could not be held responsible for his or her crimes.10 Plato, reflecting thinking that continues today, proclaimed that protecting the community was more important than punishing the wrongdoer in cases of insanity:
Someone may commit an act when mad or afflicted with disease . . . [and if so,] let him pay simply for the damage; and let him be exempt from other punishment. Except that if he has killed someone and his hands are polluted by murder, he must depart to a place in another country and live there in exile for a year.11
As authors Rita J. Simon and Helen Ahn-Redding have noted, Plato’s thoughts on insanity included the equivalent of the civil commitment mechanism of the present, in which the law allows society to institutionalize the insane against a person’s will. For Plato, the family, rather than the state, had the power: “If anyone is insane, let them not be seen openly in the city, but let relatives of such a person watch over him in the best manner they know of; and if they are negligent, let them pay a fine.”12
Aristotle, who linked mental illness and genius, summarized the theory of criminal responsibility and its implicit holding that only someone who knowingly commits a crime could be held liable for it. In the words of two scholars who have studied criminal responsibility, “To Aristotle, knowledge, rather than forethought, was the real test of responsibility: A person is morally responsible if, with knowledge of the circumstances, and the absence of external compulsion, he deliberately chooses to commit a forbidden act.”13 And in his own words, in The Nicomachean Ethics, Aristotle said of responsibility for committing acts, “The agent also must be in a certain condition when he does them; in the first place he must have knowledge, secondly he must choose the acts, and choose them for their own sakes, and thirdly his action must proceed from a firm and unchangeable character.”14 Roman law, like Aristotle’s ethical formulation, recognized that an insane person, like a child, lacked the requisite understanding to act as a responsible adult and could not execute an estate or take on debts: “The legal incapacity of the insane was absolute. Such persons were regarded as having no will of their own and so incapable of incurring any obligations involving consent, whether in the character of creditor or of debtor, because they entirely lack the understanding (intellectus) and judgment (judicium), or the capacity to comprehend the effects of their actions.”15
Roman law provided the foundation that led to the development, by the end of the twelfth century, of one of the basic articles of criminal procedure: for a person to be guilty of a crime, he or she must have a mens rea, or a guilty mind—a trait that neither the insane nor children were said to possess.16 Codification of Roman statutes on crime, insanity, and scores of other legal matters came during the reign of Byzantine emperor Justinian I (527–565 CE), who replaced the canon law of the Catholic Church with civil law and moved the Roman legal system away from Bible-based punishments. The Justinian Code’s sophisticated analysis of insanity recognized, as today’s forensics psychiatrists do, that some forms of mental illness, such as bipolar disorder, can feature cycles of bizarre and irrational behavior. The cyclical nature of some forms of mental illness would become a major part of Marjorie Diehl-Armstrong’s case. So would the question of whether she was feigning mental illness, another possibility that the ancient Romans acknowledged in cases of insanity and the mentally troubled. According to Justinian’s formulation:
If you have clearly ascertained that Aelius Priscus is in such a state of insanity that he is permanently out of his mind and so entirely incapable of reasoning, and no suspicion is left that he was simulating insanity when he killed his mother, you need not concern yourself with the question how he should be punished, as his insanity itself is punishment enough. At the same time, he must be closely confined, and, if you think it advisable, even kept in chains; this need not be done by way of punishment so much so as for his own protection and security of his neighbors. If however, as is very often the case, he has intervals of sounder mind, you must carefully investigate the question whether he may not have committed the crime on one of these occasions, and so have no claim to mercy on the ground of mental infirmity; and, if you should find that anything of this kind is the fact you must refer the case to us, so that we may consider, supposing he committed the act at a moment when he could be held to know what he was doing, whether he ought not to be visited with punishment corresponding to the enormity of the crime.17
Early English law adopted many of the Roman definitions of insanity and mental illness. Among its most significant features was the recognition that insanity, mental infirmity, and mental illness came in many forms and gradations. The early English defined “idiocy” as the equivalent of a permanent mental disability that existed from birth; the various forms of “idiot” included “fool,” “foole natural,” and “sot.”18 What society today defines as mental illness or insanity came under two categories: “lunacy” and “madness.” “Madness” denoted more of “a temporary, sometimes reversible condition”19 that was attributed to the “violently insane.”20 “Lunacy,” also known as “insanus,” described mental illness with a cyclical nature, with bouts of insanity coming in episodes, as if influenced by luna, or the moon: “‘Lunatic’ is almost always used to describe those of the insane who have lucid intervals.”21
These definitions explain one of the more famous legal treatises on insanity in early English law, by William Lambarde, a lawyer and justice of the peace. Like the formulation of Justinian I, Lambarde’s theory accounted for different kinds of mental infirmity, and it warned against malingering, or when a sane person fakes mental illness. Like the Romans, Lambarde also equated the mentally infirm and the insane with children—none are capable of using free will to knowingly choose right from wrong. In his Archeion; or, A Discourse upon the High Courts of Justice in England, which he finished by 1591, Lambarde wrote:
If a madman or a natural fool, or a lunatic in the time of his lunacy, or a child that apparently hath no knowledge of good or evil do kill a man, this is no felonious act, nor anything forfeited by it . . . for they cannot be said to have any understanding will. But upon examination it fall out, that they knew what they did, and this it was ill, then seemeth it otherwise.22
Though the early English courts recognized insanity as a defense, persuading a judge or jury to accept that defense was difficult. Another well-known definition of insanity came in 1723, at the trial in the case of Rex v. Arnold. The defendant, Edward “Mad Ned” Arnold, was found guilty of shooting and wounding his neighbor Lord Onslow despite testimony that Arnold was out of his mind at the time. The prosecution prevailed with its insistence that Arnold, his mental problems aside, knowingly bought the powder and the shot, and fired at Lord Onslow “in a lucid interval.”23
Perhaps the jurors’ rejection of the insanity defense was related to the instructions they received from the trial judge, Mr. Justice Tracy. He pronounced insanity a worthy and proper defense in general, but set a high standard for its successful application in the courtroom. Justice Tracy said that a truly insane person must have no more self-awareness than an undomesticated animal: “[I]t is not every kind of frantic humour, or something unaccountable in a man’s actions, that points him out to be much a madman as is to be exempted from punishment: it must be a man that is totally deprived of his understanding and memory, and doth not know what he is doing, no more than an infant, than a brute or a wild beast, such a one is never the object of punishment.”24 Thus was born the “wild beast test” of insanity in English jurisprudence. Arnold, the first to fail the test, was also sentenced to die, but had the penalty set aside at the request of Lord Onslow, who “respited” him. Arnold still remained incarcerated for thirty years.25
Justice Tracy’s instruction acknowledged that the truly insane were unable to “distinguish between good and evil.”26 English jurisprudence gradually developed an insanity formulation that progressed beyond the wild beast test. The change was complete—and the effects on Anglo-American law profound—in 1843, with “the most significant case in the history of the insanity defense in England”27: the case of a deranged Scottish woodcutter and assassin named Daniel M’Naghten. His prosecution has echoed through court cases ever since, including the cases of Marjorie Diehl-Armstrong. Out of his trial emerged the “M’Naghten Rules,” which established the definition of legal insanity that was the standard in England and then the United States until the 1950s.
Whether M’Naghten committed his crime was never in question. He admitted that, on January 20, 1843, in London, he fatally shot Edward Drummond, secretary to Prime Minister Robert Peel; M’Naghten said he thought Drummond was Peel.28 M’Naghten, described as “an extreme paranoiac,” also blamed Peel for his financial and personal problems, and alleged that he himself was the focus of a conspiracy that involved the pope and Peel.29 At trial, nine medical experts—including the chief medical officer at Bethlem Royal Hospital—testified that M’Naghten was insane; and even the prosecutor, Solicitor General William Follett, acknowledged that M’Naghten was mentally ill. But Follet hoped that, by relying on the wild beast test, he could also prove that M’Naghten was only partially insane when he killed Drummond and that, unlike the wild beasts, he understood right from wrong.30
The jury found M’Naghten not guilty on the grounds of insanity. The verdict was in line with the thoughts of the trial judge, Lord Chief Justice Tindal. He told the jurors that “the whole of medical evidence is on one side,” and that they had to determine whether M’Naghten was “capable of distinguishing between right and wrong.”31 M’Naghten was sent to the mental institution at Broadmoor, where he died twenty years later.
The influence of his criminal case outlasted him. His acquittal by reason of insanity enraged the public and Queen Victoria, who countered that the evidence showed M’Naghten had his wits about him when he killed Drummond. The House of Lords summoned all fifteen members of the Supreme Court of the Judicature to define the insanity law in light of the verdict. Three months later, the justices responded with answers that became known as the M’Naghten Rules, which included the most basic rule for determining legal insanity, the rule known as the M’Naghten Test. The justices wrote:
To establish a defense on the ground of insanity it must be clearly proved that, at the time of committing the act, the party accused was laboring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing, or he did know it, that he did not know he was doing what was wrong.32
The M’Naghten Test clarified the definition of legal insanity by emphasizing a right-wrong test and holding that the defendant had to be insane at the time of committing the act, which some critics said created a standard that was too rigid and failed to consider the scope of mental illness. Critics over time also said the M’Naghten Test focused too much on whether the defendant knew right from wrong, rather than on whether he or she suffered from a mental illness that would make him or her legally insane in any circumstance. The M’Naghten Test nonetheless endured, and it reflected the views on mental illness and insanity at the time—views grounded in the cognitive “right-wrong approach” that had prevailed, in various iterations, from Justinian I and the other ancients. The M’Naghten Test, like the formulations that preceded it, saw insanity as manifested in an inability to make moral decisions, rather than an inability to function because of an underlying mental illness.33 By the mid-1800s, the M’Naghten Test had become widely accepted in most courts throughout the United States.34
A would-be assassin changed the scope of the insanity defense in the United States, just as Daniel M’Naghten transformed the idea of legal insanity in England. The would-be assassin in the United States was John Hinckley Jr. His acquittal by reason of insanity in the attempted murder of President Ronald Reagan, in 1981, outside a hotel in Washington, D.C., touched off a national debate whose lasting effect was the widespread acceptance of a term in the nation’s legal lexicon: guilty but mentally ill.
Years before Hinckley shot Reagan, the legal definition of insanity had evolved beyond the M’Naghten Rules. The federal courts in the United States modified the rules in 1929 to include the “irresistible impulse exception,” which allows for an acquittal by reason of insanity if the defendant’s mental disorder prevented him or her from controlling his or her actions.35 But the insanity defense still was largely based on a right-wrong test that emphasized moral thinking over an organic approach to mental illness—that severe mental illness in and of itself was justification enough for legal insanity.
The organic approach became enshrined in American jurisprudence, for a time, starting in 1954, when the United States Court of Appeals for the District of Columbia ruled in the case of Durham v. United States, in which the accused was a mentally ill housebreaker named Monte Durham. Judge David L. Bazelon, speaking on behalf of the majority, established a standard that discarded the M’Naghten Rules for a formula that was akin to what the state of New Hampshire had been following in the cases of the legally insane since 1870.36 The new rule established in Durham, Bazelon found, “is simply that an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect.”37 In the Durham case, the Court of Appeals for the District of Columbia created a standard that was more liberal than the M’Naghten Test but was grounded in psychiatry. “This test,” as one commentator has written, “would provide for the broadest range of psychiatric expert testimony.”38 It was known as the “Durham test” or the “product test.”
The Durham test was law only in the District of Columbia, and it was “ultimately dismantled by the D.C. Circuit.”39 Its replacement came about through the 1972 decision in United States v. Brawner, which the Court of Appeals for the District of Columbia also decided. The court used the case of Archie W. Brawner Jr., convicted of second-degree murder for a 1967 slaying, to adopt the test for legal insanity that was already in the Model Penal Code of the American Law Institute (ALI), which formulated its definition in 1962. The ALI rule, like the Durham test, was less restrictive than the M’Naghten Test, and it added an element of volition that the Durham test lacked. The ALI standard, after the Brawner ruling, became law throughout the United States. Even Judge Bazelon, who wrote the opinion in the Durham case, concurred with the findings in the Brawner case. Judge Harold Leventhal wrote in the majority opinion:
The court adopts as the criterion of insanity, for all trials beginning after today, the rule stated . . . in the Model Penal Code of the American Law Institute. That rule, which has been adopted in essence by other Federal circuit courts of appeals, states: “A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of the law.” The rule of Durham v. United States . . . which excused an unlawful act if it was the product of a mental disease or defect, will no longer be in effect.40
The ALI standard was in effect on March 30, 1981, when John Hinckley, in an attempt to impress the actress Jodie Foster, shot Ronald Reagan and wounded a police officer, a Secret Service agent, and Reagan’s press secretary, James Brady, who was shot above his left eye. The twenty-five-year-old Hinckley, a failed songwriter from Oklahoma with a history of depression, pleaded not guilty by reason of insanity at his trial in United States District Court in Washington, D.C. His lead lawyer, Vincent J. Fuller, proved Hinckley’s severe mental illness by focusing on, among other things, Hinckley’s writings before the assassination attempt, including a letter he wrote to Foster the morning of the shooting. The writings, according to Fuller, “standing alone, strongly suggested that John Hinckley was utterly detached from reality and had no emotional or cognitive appreciation of it.”41
The jury acquitted Hinckley by reason of insanity on June 21, 1982. He was institutionalized at St. Elizabeth’s Hospital in Washington, D.C., where he remained until a federal judge in July 2016 found him no longer a danger to society and ordered him released to the custody of his ninety-year-old mother, near Williamsburg, Virginia.42 (Monte Durham, whose case created the Durham rule, also was institutionalized at St. Elizabeth’s). The public reaction to Hinckley’s acquittal was swift and angry, and dismayed lawmakers nationwide immediately pushed to tighten the definition of legal insanity: “Hinckley’s insanity acquittal sparked a flurry of legislative rhetoric and public inquiry about how to stop such ‘abuses’ in the future.”43
For many Americans, Hinckley knew what he was doing when he shot the president of the United States, and Hinckley should have been found guilty. They were unconvinced of Hinckley’s insanity despite even a bizarre four-page handwritten letter he sent to the New York Times two weeks after his acquittal. “The shooting outside the Washington Hilton hotel was the greatest love offering in the history of the world,” he wrote. “I sacrificed myself and committed the ultimate crime in hopes of winning the heart of a girl. It was an unprecedented demonstration of love. But does the American public appreciate what I’ve done? Does Jodie Foster appreciate what I’ve done?”44 Hinckley also wrote: “At one time Miss Foster was a star and I was the insignificant fan. Now everything is changed. I am Napoleon and she is Josephine. I am Romeo and she is Juliet. I am John Hinckley Jr. and she is Jodie Foster. The world can’t touch us. Society can’t bring us down. Jodie can’t ignore history.”45
The consternation over the Hinckley verdict produced the federal Insanity Defense Reform Act of 1984. The law did not abolish the insanity defense, as many wanted, but it eliminated the ALI test and established a stricter standard for the insanity defense in the federal courts. The act also shifted the burden of proof in federal insanity cases from the government to the defendant. No longer did the government have to prove beyond a reasonable doubt that the defendant was sane. The defense now had to prove by clear and convincing evidence—a lesser standard than beyond a reasonable doubt—that the defendant was legally insane at the time of the crime.
The Insanity Defense Reform Act made the standard for the insanity defense closer to the M’Naghten Test.46 Under the act, insanity is “an affirmative defense to a prosecution under any Federal statute that, at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of his acts. Mental disease or defect does not otherwise constitute a defense.”47
Three states—Montana, Idaho, and Utah—eliminated the insanity defense following the Hinckley verdict. Others adopted standards that adhered to the M’Naghten Test (as in Pennsylvania) or the Durham test, in their original or modified formats. Among the most popular of the reforms was the introduction, at the state level, of the verdict of guilty but mentally ill. The Pennsylvania General Assembly passed the law that established the verdict in that state on December 15, 1982, six months after Hinckley’s acquittal. The law in Pennsylvania, as in other states, did not replace the insanity defense with the defense of guilty but mentally ill. The new defense gave juries “an alternative verdict for mentally ill offenders. Those raising the insanity defense can be found guilty, not guilty, not guilty by reason of insanity, or guilty but mentally ill.”48 A verdict of guilty but mentally ill also became an option for defendants who did not plead insanity but who still suffered from mental illness.
A defendant found guilty but mentally ill, or who pleads guilty but mentally ill, is treated the same as a guilty defendant at sentencing. But, perhaps most important for lawmakers and the public, a defendant found guilty but mentally ill is sentenced to prison, where he or she is required to get mental health treatment, rather than confined to a mental institution, where a specific length of institutionalization was never guaranteed. In Pennsylvania and elsewhere, the adoption of the alternative verdict of guilty but mentally ill signified the latest effort to deal with a legal tension that had existed since the ancients: how to recognize mental illness and protect the community: “The wave of reform following John Hinckley’s acquittal in 1982 represented legislative efforts to restore a balance in the operation of the insanity defense between individual rights and public protection, a balance that the public would deem acceptable.”49
The definition of guilty but mentally ill in Pennsylvania reads: “A person who timely offers a defense of insanity . . . may be found ‘guilty but mentally ill’ at trial if the trier of facts finds, beyond a reasonable doubt, that the person is guilty of an offense, was mentally ill at the time of the commission of the offense and was not legally insane at the time.”50 The definition eventually would become familiar to Marjorie Diehl-Armstrong.