The M'Naghten Case: How an 1843 Homicide Shaped the Insanity Defense
Author: Ukrainian Psychological Hub · Published: October 11, 2026 · Editorial Policy
The M'Naghten case began with a killing in London in January 1843 and became one of the most influential events in the history of criminal responsibility. Daniel M'Naghten was acquitted of the murder of Edward Drummond on the ground of insanity. The public and parliamentary reaction prompted judges to articulate the legal principles later called the M'Naghten Rules. Those rules became a foundational approach to determining when a mental condition may excuse criminal responsibility.
The central distinction is historical and legal: the jury's decision in March 1843 was one event; the judges' answers to questions from the House of Lords in June 1843 were another. The latter became the widely cited statement of law. Their influence remains visible in modern debates over the insanity defense, although jurisdictions apply different legal tests. The original reported decision, 1843 parliamentary debates, and the U.S. Supreme Court's Kahler v. Kansas provide three complementary anchors for understanding this history.
This historical case study reconstructs what the records establish, explains the medical testimony in its nineteenth-century context, distinguishes the original rules from later interpretations, and follows their influence into contemporary forensic psychology and U.S. and English law. Historical descriptions of mental disorder in this article are attributed to their sources; they are not present-day diagnoses of M'Naghten.
Who Was Daniel M'Naghten?
Daniel M'Naghten, also spelled McNaughtan, McNaughton, and M'Naghtan in different historical sources, was a Scottish man whose name became attached to the insanity defense through the legal response to his trial. Spellings vary across court records, medical histories, and later scholarship. The form M'Naghten is particularly recognizable from the reported rules and modern legal commentary; spelling variation does not identify separate defendants.
Accounts of his life describe work in Scotland, troubling beliefs that he was being followed or persecuted, and his movement to London. The historically significant question is what the witnesses actually said about his beliefs and functioning, rather than whether a later writer can retrospectively assign a modern diagnostic label. The criminal proceedings document a homicide and testimony about mental state; they do not supply the comprehensive clinical data needed for a contemporary diagnosis. For a source-focused overview of the wider legal development, see Moran's historical analysis.
What Happened on January 20, 1843?
On January 20, 1843, Edward Drummond, a civil servant and private secretary to British Prime Minister Sir Robert Peel, was shot in London. Drummond died from his injuries on January 25. M'Naghten was prosecuted for his murder. These dates and the identity of the victim are established in the reported criminal proceeding and are consistent with the contemporary biographical record of Edward Drummond.
Popular accounts frequently state that Peel was the intended victim and Drummond was mistaken for the prime minister. This is a historically familiar reconstruction, but the claimed contents of M'Naghten's mind should be distinguished from the observable shooting and the testimony introduced to explain it. Later biographies, journalistic retellings, and courtroom interpretations do not all carry the same evidentiary weight. The essential trial fact is that Drummond was killed and that the defense presented evidence of M'Naghten's mental state at the relevant time.
The fact that a person selected a target, obtained a weapon, or carried out apparently organized behavior may be relevant evidence. It does not by itself establish that the individual understood the act's wrongfulness under a particular legal standard. Conversely, the presence of a fixed belief or unusual experience does not by itself prove a legal excuse. The importance of this distinction runs through the entire M'Naghten legacy.
The March 1843 Murder Trial
M'Naghten was tried at London's Central Criminal Court, the Old Bailey, on March 3 and 4, 1843. The prosecution concerned Drummond's death; the defense relied on evidence about mental disturbance and its relationship to the act. Contemporary legal and medical testimony was framed using the vocabulary available at the time, including descriptions of delusion and partial insanity. The reported case and a peer-reviewed historical review of the trial place these events in their immediate context.
Medical witnesses described what they understood to be genuine delusional beliefs. Some had examined M'Naghten and others formed opinions after hearing evidence in court. Their positions and access to evidence therefore differed. Later scholarship specifically discusses the roles of Dr. Edward Monro and Dr. Forbes Winslow and the contrasting foundations of their opinions. Such differences matter today because expert reliability depends on the information and methods supporting the conclusion, not simply on professional status.
The court ultimately returned an acquittal on the ground of insanity. An acquittal meant that the jury did not impose the criminal liability ordinarily attached to the homicide under the applicable legal framework. It did not mean that the killing had not occurred, that Drummond was unharmed, or that M'Naghten had been declared medically well. Historical accounts and subsequent legal discussions describe his detention following the verdict. As Moran explains, the interaction between insanity verdicts and confinement had already been shaped by earlier events in English legal history.
What Did the Medical Experts Actually Establish?
The contemporaneous experts offered opinions that M'Naghten's beliefs were disturbed and relevant to his conduct. The testimony was clinically framed by nineteenth-century medical concepts. A historian can report those findings and analyze their forensic significance without converting them into a modern DSM or ICD diagnosis.
A modern clinical diagnosis requires evidence about symptoms, duration, functioning, alternative explanations, substance effects, medical conditions, and the applicable diagnostic criteria. The original trial record documents particular observations and opinions, but its vocabulary does not map one-to-one onto modern categories. It would therefore be unsound to present schizophrenia, delusional disorder, or another present-day diagnosis as a fact personally verified in 1843.
Even when a diagnosis is established, criminal responsibility asks an additional question about legally relevant capacities at the time of an act. A psychiatric diagnosis and a legal finding answer different questions. The American Academy of Psychiatry and the Law's practice guideline expressly separates the presence of disorder, its possible relationship to the alleged conduct, and satisfaction of the particular jurisdiction's legal standard. The M'Naghten case is an early illustration of why these layers must be examined separately.
The Acquittal and Its Immediate Consequences
The March verdict provoked intense debate. The House of Lords debate of March 13, 1843 shows legislators grappling with public fear, the treatment of people experiencing serious mental disturbance, and uncertainty about how law should judge responsibility. That record is particularly valuable because it captures responses close to the event, rather than relying entirely on later interpretation.
The debate also illustrates a recurring problem in forensic legal policy: an emotionally powerful case can accelerate demands for a clear rule, but the clarity of a verbal formula does not settle every difficult factual or clinical question. Legislators recognized that some people experiencing delusions could appear organized and rational in other settings. Observing functional behavior in one domain, therefore, did not dispose of questions about an individual's beliefs or appreciation of an act's consequences.
Parliament did not merely rehear the verdict. The controversy led to a request for judicial clarification, and that later judicial response acquired the distinctive historical influence now associated with the case.
How the House of Lords Produced the M'Naghten Rules
Following the acquittal and parliamentary discussion, the House of Lords sought the judges' opinions on questions about criminal responsibility and mental disturbance. The judicial answers associated with May 26 and June 19, 1843, were recorded as Daniel M'Naghten's Case, commonly cited as 10 Clark & Finnelly 200 or 8 English Reports 718. The original law report is the controlling historical source for the formulation.
The distinction between the original trial and these later questions is fundamental. The familiar M'Naghten formulation was not a statute enacted in advance of the homicide, and it was not a modern psychiatric test applied to an examination of the defendant. It was an authoritative legal response, expressed by judges after the trial, to general questions about when mental disease may affect criminal liability.
The House of Lords' procedure also had limitations. The report records Justice Maule's reservations about giving broad abstract answers without the benefit of argument or a concrete set of facts. A general rule necessarily leaves interpretive work to later judges and juries. That observation helps explain why the M'Naghten language generated disagreements over the meaning of disease, reason, knowledge, and wrongfulness.
What Do the M'Naghten Rules Actually Say?
The best-known formulation says that an insanity defense requires proof that, at the time of the act, a defect of reason arising from disease of the mind left the accused unable to know the nature and quality of the act, or unable to know that it was wrong. This is a paraphrase of the original historical language; the reported judgment and the University of Minnesota Law Library's case collection preserve the source formulation.
The words describe a legal excuse attached to a relevant mental state at a specified time. They do not say that anyone with a psychiatric diagnosis is exempt from criminal law. They do not assign an actuarial probability that the defendant will commit another offense. They do not provide a standardized psychometric cutoff. Their legal role is to guide a court deciding culpability under the applicable law.
The two familiar pathways are commonly described as the nature-and-quality pathway and the wrongfulness pathway. Both are cognitive in their traditional emphasis, although interpretation varies. The first examines whether the defendant understood the character of the act; the second concerns awareness of its wrongfulness. The exact meaning of these terms depends on the jurisdiction and judicial interpretation.
First Pathway: Understanding the Nature and Quality of the Act
The nature-and-quality question concerns what the accused understood about the conduct at the moment it occurred. The relevant issue could arise when a mental condition profoundly distorts perception of what one is physically doing or what the act means. It is not simply a question of whether the person remembers events later.
Someone can remember a sequence, describe an action, and still have been affected by disturbed beliefs. Whether those beliefs meet the particular legal test requires close examination of their content and effect. Similarly, confused or disorganized behavior does not automatically establish an inability to understand the nature of the conduct.
Forensic professionals therefore look for time-specific evidence from statements, contemporaneous behavior, medical information, witnesses, and records. The reconstruction is retrospective and may be incomplete. The AAPL insanity-defense guideline recommends integrating multiple independent sources and explicitly addressing discrepancies rather than treating an interview or score as dispositive.
Second Pathway: Knowing That the Act Was Wrong
The meaning of wrongfulness is one of the most disputed elements in M'Naghten-derived law. Does wrong mean prohibited by law, contrary to ordinary community morality, or contrary to a defendant's personal moral beliefs? These possibilities may produce different answers to the same hypothetical case.
Goldstein and Rotter's analysis documents different judicial interpretations of legal wrongfulness, objective moral wrongfulness, and subjective moral wrongfulness. The historical M'Naghten language did not eliminate later controversy. For a clinician preparing an opinion, the relevant standard must be identified before translating clinical observations into a forensic assessment.
The difference is especially important when an individual believes an act is legally prohibited but also believes, because of disturbed perceptions, that it is commanded or justified by some exceptional authority. The defendant's belief is evidence about mental functioning; the applicable law determines its legal significance. An expert must not substitute personal moral judgment for the court's controlling legal test.
Delusions: Why the Legal and Clinical Questions Diverge
The original rules also discuss a person acting under a partial delusion. They suggest assessing responsibility, in that setting, as though the supposed facts behind the delusion were true. This approach is historically revealing because it tries to translate an altered understanding of circumstances into a conventional legal analysis. It also creates difficulties when the imagined circumstances are complex, inconsistent, or bound up with distorted judgments about authority.
Modern psychiatry recognizes that symptoms can affect perception, reasoning, motivation, emotional experience, and behavior in different ways. Legal definitions concentrate selectively on capacities relevant to culpability. Consequently, a person may experience delusions without meeting a legal insanity standard, and a legal assessment may depend on the relationship between a particular belief and a particular act.
The key forensic task is to identify what the person reportedly believed, how the belief related to the conduct, what independent evidence supports that reconstruction, and which legally defined capacity is at issue. The AAPL guideline describes this as a structured, individualized analysis rather than a simple deduction from diagnosis. The existence of psychosis does not itself predict violence or establish criminal responsibility.
Planning, Apparent Rationality, and Legal Responsibility
One persistent misconception is that preparation or apparently goal-directed behavior automatically proves sanity in the legal sense. Planning, concealment, or attempts to escape may be evidence bearing on awareness and intent. Their meaning depends on the conduct and the applicable legal criterion. Legal insanity is not the same as total confusion in every domain of life.
The opposite shortcut is equally weak: unusual speech, unconventional beliefs, or a history of treatment cannot automatically establish that a person lacked relevant legal capacities at the time of a crime. Evidence must connect the individual's mental functioning to the specific legal issue. Courts and evaluators have to assess competing explanations and the possibility that observations support more than one inference.
This was an important tension in the nineteenth-century debate, and it survives in contemporary forensic assessments. The House of Lords proceedings describe precisely the difficulty of interpreting individuals who appear capable in many situations but have circumscribed disturbed beliefs.
The Difference Between an Insanity Defense and Competency to Stand Trial
Insanity is an offense-time inquiry into criminal responsibility. Competency to stand trial is a present-time inquiry into whether a defendant can participate in the legal proceedings to the extent required by applicable law. A defendant could be competent to stand trial while raising an insanity defense for a previous act, or incompetent now without qualifying for an insanity defense.
M'Naghten is a historical source for criminal-responsibility law, not the foundation of every modern competency or capacity test. This distinction prevents confusion between an individual's ability to understand a court hearing and that person's mental functioning during a past offense. For the complete contemporary distinction, see Competency to Stand Trial vs. Insanity Defense: Key Differences.
The broader psychological and legal evidence concerning responsibility belongs in our Criminal Responsibility and the Insanity Defense guide. The present article maintains a narrower historical intent: what M'Naghten's own prosecution contributed and why the subsequent formulation endured.
How the Rule Spread Beyond England
The M'Naghten formulation strongly influenced common-law jurisdictions and became an important reference point in American insanity-defense law. Its reception, however, varied. Judges and legislatures adopted, supplemented, modified, and sometimes rejected aspects of the rule. It is historically inaccurate to assume that every country or American state uses the same version.
A useful scholarly reconstruction is Moran's comparison of the Hadfield and M'Naghten cases, which shows how political reaction and judicial development helped shape modern insanity defenses. Allnutt, Samuels, and O'Driscoll review the historical formulation and differing interpretations in legal practice.
Legal transmission also changes the practical meaning of familiar words. The phrase disease of the mind can have a specialized legal meaning different from a current psychiatric diagnostic category. The terms wrong, know, appreciate, and mental disease or defect cannot be assumed interchangeable across jurisdictions.
The Model Penal Code and the Expansion of the Test
Twentieth-century U.S. reform introduced alternative tests. Section 4.01 of the American Law Institute's Model Penal Code became influential because it referred to a lack of substantial capacity to appreciate criminality or wrongfulness, or to conform conduct to legal requirements. This approach included a volitional dimension absent from the narrow conventional account of M'Naghten. The U.S. Department of Justice's historical explanation documents use of the Model Penal Code formulation in federal courts before the 1984 federal reform.
The difference between knowing an act is wrong and appreciating its wrongfulness is consequential. Appreciation is frequently interpreted as encompassing a fuller understanding of the act's significance, while substantial capacity recognizes degrees of impairment. However, the exact legal meaning comes from case law and legislation, not from a general psychological measurement scale.
The Model Penal Code approach is an independent legal development, not a correction retroactively applied to M'Naghten's own jury. Historical interpretation should keep the 1843 proceeding and later legal reform chronologically distinct.
The Federal U.S. Insanity Defense After 1984
The federal Insanity Defense Reform Act of 1984 changed the U.S. federal test after another historically prominent case, the attempted assassination of President Ronald Reagan and the insanity verdict involving John Hinckley Jr. Today 18 U.S.C. § 17 requires that, because of a severe mental disease or defect, the accused was unable to appreciate the nature and quality or the wrongfulness of the acts. The statute also assigns the defendant the burden of proving the defense by clear and convincing evidence.
The federal standard omits the Model Penal Code's separate inability-to-conform pathway. The Department of Justice's explanation of the federal test confirms that difference. It is useful to recognize the M'Naghten influence on this cognitive framing while acknowledging that the federal statute has its own wording and burden of proof.
State law must be checked separately. A federal definition is not an automatic description of insanity defenses in state prosecutions, and neither is a particular state's jury instruction a universal psychological rule.
What the U.S. Supreme Court Said in Kahler v. Kansas
The U.S. Supreme Court's 2020 decision in Kahler v. Kansas directly addressed the constitutional significance of historical insanity tests. The majority held that the Due Process Clause did not require Kansas to adopt an insanity defense based on a defendant's inability to recognize the moral wrongfulness of the act. The Court considered the variety of historical approaches, including the M'Naghten formulation and alternatives developed in American jurisdictions.
The case is particularly important for interpreting M'Naghten accurately. Its historical influence is substantial, but the Supreme Court did not elevate one formulation into a uniform constitutional rule binding all states. Justice Breyer's dissent argued that the moral-incapacity protection held a more foundational place in legal tradition. Both opinions show the continuing importance of the underlying dispute.
This is a legal disagreement about standards of responsibility and constitutional requirements. It cannot be resolved merely by determining whether one diagnostic label appears in a medical record.
England and Wales: Continuity and Reform Debates
In England and Wales, the legal framework of insanity retains a strong relationship with nineteenth-century M'Naghten principles. The Law Commission has criticized the age and terminology of the rules, their imperfect fit with medical understanding, and their relationship with automatism. Its 2013 discussion project identified significant problems with how the categories operate in modern law.
The Law Commission also describes a further defense-of-insanity reform project, which its published project page characterizes as upcoming rather than completed. Reform proposals and critical discussion therefore should not be confused with statutory change already enacted. English and Welsh legal practice must be interpreted through current statutes and cases as well as the historical rules.
Terms such as insanity are retained here because they are established legal labels in particular jurisdictions. They do not describe a modern clinical diagnosis, the dignity of a person, or a single medically defined condition.
What Does Forensic Psychology Learn From This Case?
The enduring psychological lesson is the need to separate observation, inference, clinical interpretation, expert opinion, and legal finding. A witness may report conduct. A clinician may describe symptoms and formulate a diagnosis. An evaluator may assess how a mental condition could have affected specific abilities at a particular time. A court then applies the legal standard. Each step has its own evidentiary requirements.
An insanity evaluation is retrospective. Experts may have incomplete contemporaneous records, conflicting witness statements, changes in reported symptoms, and strong incentives affecting accounts of the events. No modern instrument can reconstruct the defendant's exact historical experience with certainty. For a systematic account of interview, collateral data, diagnosis, legal questions, and the limits of expert conclusions, see the AAPL professional guideline.
Evidence-based forensic practice also requires independence, transparency about uncertainty, and attention to cultural and linguistic context. Differences in expression, interpretation, and access to records can complicate an assessment. A score, symptom checklist, or behavioral sign never substitutes for legal analysis or corroborated case-specific evidence. Our Forensic Psychological Assessment: Purpose, Methods, and Limits article examines the contemporary assessment process in detail.
Psychological Evidence, Expert Opinion, and the Jury's Role
The medical testimony in 1843 demonstrated the growing significance of specialized knowledge in criminal proceedings. It also exposed a problem that remains contemporary: the expert's professional interpretation and the judge or jury's decision about criminal responsibility must occupy different roles. Whether a professional can give an ultimate-issue opinion, and with what restrictions, depends on the legal system.
The AAPL guideline emphasizes that the examiner must understand the jurisdiction's legal question and present a reasoned assessment. Its guidance is explicitly not a guarantee of accurate reconstruction. The 1988 analysis of wrongfulness standards likewise shows why an expert must know what legal meaning the court assigns to apparently ordinary language.
The M'Naghten proceeding is therefore historically important for expert testimony as well as for criminal responsibility. It reveals the limits of medical classification as a direct answer to legal culpability.
Did the M'Naghten Rules Create the Insanity Defense?
No. Legal systems had already considered mental incapacity in criminal responsibility. Earlier English cases and debates shaped what happened in 1843. The distinctive M'Naghten contribution was the influential articulation of a legal rule after a politically prominent acquittal, rather than the invention of an insanity defense from nothing.
Moran's historical article places the case alongside James Hadfield's 1800 acquittal. Allnutt and colleagues trace a longer path from older conceptions of insanity to nineteenth-century rules. These historical comparisons prevent a simplified account in which one murder trial is credited with creating the entire field of insanity law.
Common Myths About the M'Naghten Case
Myth: The jury applied the later M'Naghten Rules in March 1843
The famous rules were formulated through the judges' answers to the House of Lords after the verdict. The trial and the rule-making response must be dated separately. The law report is the main documentary source.
Myth: An insanity acquittal means the killing never happened
The verdict concerns criminal responsibility, not whether the historical event occurred. Drummond died, and the case concerned M'Naghten's responsibility for his death. Legal acquittal on this ground and factual reconstruction answer different questions.
Myth: A person with delusions must be legally insane
Delusions or other symptoms are clinical evidence that may or may not meet a specific legal test. The particular belief, its relation to the conduct, the time of the offense, independent corroboration, and the jurisdiction's standard must be considered. The AAPL guideline makes these steps explicit.
Myth: The rules are identical everywhere today
American states, U.S. federal law, England and Wales, and other legal systems use distinct formulations or interpretations. Kahler rejects a constitutional demand that every American state employ a single moral-wrongfulness formula.
Myth: An apparently planned act conclusively rules out insanity
Conduct that looks organized is relevant to a forensic reconstruction, but its meaning is case-specific. Neither planning nor disorganization decides the legal issue without the legally required contextual analysis.
Myth: Modern psychiatrists can diagnose M'Naghten from the historical narrative
The available record supports documentation of nineteenth-century observations and opinions. It cannot sustain a clinical evaluation using present-day diagnostic criteria with the completeness and reliability required to present a modern diagnosis as established fact.
How to Read the Historical Evidence Responsibly
The strongest evidence is the original legal reporting and parliamentary discussion, supplemented by contemporaneous trial material where available. Peer-reviewed historical scholarship helps situate those documents within medical practice and legal reform. Later biographies and popular retellings can be useful for identifying public myths, but they carry less weight for disputed psychological interpretations.
Several distinctions should remain explicit. The shooting and the death of Drummond are documented events. Testimony that M'Naghten had delusional beliefs is a documented historical clinical opinion. The jury's verdict is a documented legal outcome. The June answers to the House of Lords are an authoritative legal statement. Claims about a precise modern diagnosis, hidden subjective motivations, or what a different court would have decided are later interpretations or counterfactuals.
This hierarchy of evidence makes the historical case useful for a psychological encyclopedia. It helps readers understand how legal systems use mental-health evidence without turning a single notorious incident into a generalized statement about people who experience psychiatric symptoms.
Frequently Asked Questions
What is the M'Naghten case?
It is the 1843 English murder case involving Daniel M'Naghten and Edward Drummond, followed by the House of Lords' request for judicial answers that produced the influential M'Naghten Rules. Those answers concerned the conditions in which mental disease could affect criminal responsibility.
Who did Daniel M'Naghten kill?
He shot Edward Drummond, the private secretary to Prime Minister Robert Peel, on January 20, 1843. Drummond died on January 25. The trial took place in March 1843.
Was M'Naghten found guilty?
He was acquitted on the ground of insanity. The verdict was a legal judgment about criminal responsibility under the law and evidence presented in the case, not a finding that the fatal shooting had not happened.
When were the M'Naghten Rules established?
They arose from judicial answers to the House of Lords after the March trial, in proceedings reported with May 26 and June 19, 1843 dates. The frequently cited legal report is 10 Cl. & Fin. 200; 8 E.R. 718.
What is the M'Naghten right-and-wrong test?
In its familiar form, it focuses on whether a defect of reason caused by disease of the mind prevented the accused from knowing the nature and quality of the act or knowing that it was wrong at the time. Its modern application depends on a jurisdiction's law and interpretation.
Did M'Naghten have schizophrenia?
A modern diagnosis cannot be established from nineteenth-century testimony alone. Medical witnesses described delusional beliefs and expressed opinions in their period's terminology. A present-day diagnosis requires additional clinical evidence and a contemporary diagnostic assessment.
Is the M'Naghten Rule the same as the U.S. federal insanity defense?
They are related but not identical. The current federal defense is governed by 18 U.S.C. § 17, including its severe-mental-disease-or-defect threshold, appreciation language, and clear-and-convincing-evidence burden.
Does a psychiatric diagnosis establish legal insanity?
No. Diagnosis, offense-time functional capacity, forensic opinion, and legal finding are distinct. The relevant statute or case law defines what must be established. Clinical evidence informs the court's decision but does not replace it.
Why is the case still important in forensic psychology?
It shows how clinical observations can become legally consequential and how difficult it is to translate individual mental functioning into categorical standards of criminal responsibility. It also demonstrates why historical facts, psychiatric opinions, and legal judgments require separate treatment.
Related Articles
References
Allnutt, S., Samuels, A., & O'Driscoll, C. (2007). The insanity defence: From wild beasts to M'Naghten. Australasian Psychiatry, 15(4), 292–298. https://doi.org/10.1080/10398560701352181
American Academy of Psychiatry and the Law. (2014). AAPL practice guideline for forensic psychiatric evaluation of defendants raising the insanity defense. Journal of the American Academy of Psychiatry and the Law, 42(4 Supplement), S3–S76. https://jaapl.org/content/42/4_Supplement/S3
Goldstein, R. L., & Rotter, M. (1988). The psychiatrist's guide to right and wrong: Judicial standards of wrongfulness since M'Naghten. Journal of the American Academy of Psychiatry and the Law, 16(4), 359–367. https://jaapl.org/content/16/4/359
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Kahler v. Kansas, 589 U.S. 271 (2020). Supreme Court of the United States. https://www.law.cornell.edu/supremecourt/text/18-6135
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United States Congress. (1984, as amended). 18 U.S.C. § 17: Insanity defense. Office of the Law Revision Counsel. https://uscode.house.gov/view.xhtml?req=%28title%3A18+section%3A17+edition%3Aprelim%29
United States Department of Justice. (n.d.). Criminal Resource Manual, § 636: Insanity—Prior law. https://www.justice.gov/archives/usam/criminal-resource-manual-636-insanity-prior-law
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