Also known as the “right-wrong” test, the M’Naghten Rule is a legal standard used to determine whether a defendant can be excused from criminal liability by reason of insanity.
Defendants are presumed to be sane and have a sufficient degree of reason to be responsible for their crimes. To rebut this presumption one of the following is required:
To establish a defence on the ground of insanity, it must be clearly proved that at the time of committing the act the party accused was labouring 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 as not to know that what he was doing was wrong. [1]
The M’Naghten Rule remains the most common insanity standard across U.S. state jurisdictions as of the time of this writing. [2]
The other cases discussed below either contributed to the development of the M’Naghten Rule or utilized the criteria of insanity established by M’Naghten.
On January 20, 1843, Daniel M’Naghten, a Scottish woodturner, murdered Edward Drummond, secretary to the Prime Minister of the United Kingdom. In the weeks prior to the incident, M’Naghten was seen and recognized loitering near the eventual site of the murder on Downing Street, a London street crowded with government offices and residences. His regular presence even led others to believe that he was a plain-clothes police officer, a characterization that he would falsely confirm. That January afternoon, while Drummond was walking along Downing Street, M’Naghten shot him point-blank from behind.
M’Naghten attempted to fire again, this time from his other single-shot pistol, but was foiled by a nearby police constable and other bystanders. [3] Drummond was able to walk home and have the bullet removed, but the wound was ultimately fatal. Drummond died five days later. Although M’Naghten's motive for the shooting was never definitively uncovered, the leading theory is that the real target was the Prime Minister, Robert Peel, and Drummond had the misfortune of being mistaken for him.
M’Naghten pleaded not guilty to the willful murder charge. He only admitted to the firing of the gun, on the grounds that he was “driven to desperation by persecution.” In the months before the shooting, M’Naghten believed that Catholic priests, Jesuits, and members of the Tories, a British political party, were incessantly spying on him as part of a conspiracy to falsely accuse him of crimes and ultimately to murder him.
At trial, evidence was put forward that M’Naghten was not in a “sound state of mind” at the moment of the murderous act. According to M’Naghten’s medical expert testimony, M’Naghten’s delusions were so real to him that his state of mind “carried him away beyond the power of his own control.” [4]
M’Naghten was ultimately excused, receiving a jury verdict of not guilty by reason of insanity. The verdict drew intense public attention and controversy, and the issue was taken up in Parliament with a view to a statutory response. Queen Victoria also expressed her formal disapproval of the verdict. The House of Lords called the common law judges before them to review the case and provide a suitable legal definition of insanity. A large majority of the judges agreed that the jury at the trial was improperly instructed and approved a definition of insanity that became the M’Naghten Rule.
After his acquittal, M’Naghten was forcibly put in a mental institution where he spent the remainder of his life.
Prior Evolution of the Insanity Defense
Although the M’Naghten Rule is recognized as the first legal test for the insanity defense, the foundation was laid prior to M’Naghten’s paranoia-fueled tales of ubiquitous persecution. [5]
The 1724 case of Rex v. Arnold established the “wild beast test.” [6] Under this test, a defendant would be excused from punishment if he was found to “be a man that [was] totally deprived of his understanding and memory, and [did] not know what he is doing, no more than an infant, than a brute or a wild beast.” This earlier test focused on defendants’ cognitive rather than moral failings.[7]
An English nobleman, Lord Onslow, was riding back from fox-hunting when the criminal act occurred. Mr. Flutter, one of Onslow’s companions, noticed Arnold coming toward them with a gun readied and aimed in their direction. Mr. Flutter asked him what he was doing but received no answer. Arnold then took a couple of steps forward and aimed his gun. Onslow’s companions testified that it appeared Arnold was aiming for Onslow’s head. Arnold shot, and the bullet hit Onslow in the shoulder, knocking him off his horse. Onslow’s companion, Mr. Parsons, went after Arnold, eventually apprehending him, and Onslow exclaimed “you villain, you have killed me!”
The Crown contended that Arnold thought of Onslow as “an enemy to his country,” and that the attempt on Onslow’s life was a “good service” to God and the nation. At trial, Arnold said he was sorry for the accident and did not know why he did it, to which the Crown replied that “the devil worked with him, [standing] at his right hand, and directed him.” Some town residents testified that they did not think of Arnold as a madman, but rather as a sullen, foul-mouthed, slightly strange, distempered man. As one witness testified, he took Arnold not for a “madman, or a wise man, nor a fool.” However, others, including Arnold’s siblings and mother, testified that they believed him to be a madman at times, due to his unprovoked verbal attacks on his father, random “passions of cursing and swearing,” gun-shooting, and bursts of “foolish laughter” with a “grin like any madman. [8]
The jury determined that Arnold did not pass the wild beast test. It found in favor of the Crown’s argument; and was swayed by some of the witnesses’ testimonies that Arnold did not act from madness, but rather by wicked and “deliberate design.” [9] Arnold was sentenced to death; however, at Onslow’s request, his sentence was reprieved to life in prison.
Another notable development in the insanity defense prior to the establishment of the M'Naghten Rule was Rex v. Hadfield, which suggested that if a defendant’s delusions dominate and displace actual reality, then he would be excused from criminal liability for the resulting unlawful behavior. [10] Additionally, Rex v. Lord Ferrers, denied the availability of partial insanity as a defense. [11]
More Resources:
Common Law Applications of the M’Naghten Rule
Regina v. Southey (1865)
Citation(s): 4 Foster & Finlayson's Nisi Prius Reports 864
In Regina v. Southey the M’Naghten Rule was cited as a standard to determine the guilt of the man accused.
Stephen Forwood, having adopted the name Ernest Southey, was charged with the willful murder of his estranged wife and daughter in their Ramsgate home. Southey went off to London, leaving them in Ramsgate, and had not attempted to contact them. Southey had not seen them for over a decade prior to their murders on August 10th, 1864.
While in London, Southey took up a job as a billiards marker but was later reported by a debtor for attempted extortion and intimidation related to the game. In response, he wrote a long letter to a local daily newspaper “containing a perfectly coherent history of his life, and account of the particular matter.”
During this time in London, Southey had an affair with a married woman, Mrs. White, with whom he had three sons. When Mrs. White left Southey, things took a tragic turn. After her departure to Australia, Southey went to her husband’s home, took the three sons to a coffee house, and fatally poisoned them.
The next day, dressed in disguise with fake facial hair and glasses, Southey made his way back to Ramsgate in search of his estranged wife, Emma. On the morning of August 10th, they conversed in a common area of the home. He told her he lost a lot of money and was suffering, asking her to “mind, I had reproaches enough last night, let me have no more of them today,” alluding to the murdering of his sons back in London. After much insistence, Emma finally accepted his pleas to speak with her alone upstairs, away from her housemates. About a half-hour later, and about five minutes after their daughter, Emily, came into the room, the housemates heard gunshots. He was seen discarding his disguise just before he was seized. Upon police arrival, he seemed “cool and collected” and did not deny his actions. Later on, underneath the body of his deceased wife, the police found a newspaper clipping of his letter to the paper, meticulously removed from its pages.
The defense’s medical witnesses determined that he was insane. In seeing him a couple of days prior, they characterized Southey as “quite unhinged” with a quick temper, “rambling manner,” and a “wildness about his eye.” When asked about his letters to the paper and one written to his friend from prison, the witnesses came to the conclusion that he suffered from chronic insanity accompanied by lucid intervals.
The prosecution accused him of feigning insanity to build his defense. While in prison, he privately wrote to a friend, “my life is over; I shall have to justify myself from terrible charges” (alluding to the murder of Mrs. White’s sons) and wrote other letters about his affairs that were “quite sane, sensible, and intelligent.” Additionally, testimony from the prison’s medical team and administration (who saw him every day post-arrest) and testimony from Mrs. Forwood’s housemates (who’d known him for several years prior) all agreed that he seemed sane and comprehensive of his actions. One of the witnesses acknowledged that he had some fleeting “fits of excitement” but that he was overall a “very intelligent man” with the object of establishing an insanity defense. At closing, the prosecution reminded the jury that the defense’s witnesses examined Southey very shortly (one for only fifteen minutes) with the purpose of building his case.
The jury eventually found Southey of a sane mind and sentenced him to death.
Regina v. Townley (1863)
Citation(s): 3 Foster & Finlayson's Nisi Prius Reports 839
Townley was charged and found guilty of the murder of his former fiancée, Elizabeth Goodwin. At issue in this case was whether, by applying the M’Naghten rule, his asserted insanity defense would excuse him from this verdict.
Townley and Goodwin were in a long-distance engagement for approximately three years when Goodwin wrote a letter to break off the engagement after meeting someone else. After an exchange of letters, Goodwin accepted Townley’s request to see her and talk about it in person. Townley made his way over to Goodwin’s residence, where she lived with her grandfather.
A couple of hours after Townley and Goodwin went on a walk for their discussion, Goodwin, with her throat cut and on the cusp of death, was found by one of the laborers nearby. Townley was just up the road and walked back to help the laborer carry her body back into her home, admitting that he committed the murder, should be hanged for it, and repeatedly saying “Poor Bessie… You should not have proved false to me.” When they finally arrived back, Goodwin had died, and Townley also told her grandfather that he did it. When asked why, Townley responded that “she has deceived me; and the woman that deceives me must die.” When the police came, Townley again admitted to his action, acting with cool indifference and without remorse.
At trial, doctors testified about his behavior while imprisoned. The doctors testified that when they asked about Townley’s motive, Townley responded that he already considered Goodwin as his wife. In Townley’s opinion, his wife was like any other piece of property; he acted as he would if anything was taken unlawfully from him. Pushing back against the view, one doctor asked why he would not seek restitution for stolen property through the legal system. Townley responded that he wholeheartedly believed, because he did not ask to be born, that he had the “liberty to think and act as he pleased,” asserting that neither the law nor any individual had the authority to restrain him. Both doctors testified that Townley knew that the act was legally punishable and others saw it as wrong, but that he had no regrets. Both doctors, and some other witnesses that saw him shortly before the murder, did not think he was delusional–rather that he had unreasonable opinions and was at times an impulsive person; he was otherwise just a pessimistic man.
In court, the judge instructed the jury that if Townley was not under a delusion when he committed the murder, knew that his action would probably be fatal, and knew that his action was unlawful, [12] then he should be found guilty, referencing the M’Naghten Rule. The jury was reminded that delusions and insanity are different from having eccentricities, experiencing devastating jealousy, or having deeply unpopular immoral opinions. Ultimately, taking Townley’s statements heavily into consideration, the jury found him guilty without the excuse of insanity.
12) Unlawful under both “the law of God and man.” Return to text
Freeman v. People (1847)
In 1846, William Freeman was arrested and accused of the brutal murder of four members of the Van Nest family in northern New York state. Freeman, a Black man, had been previously beaten while in prison, which resulted in permanent brain damage.
Freeman was convicted by the trial court, despite the efforts of a young William Seward, who had joined the defense team. At trial, Seward and his team raised an insanity defense and introduced medical experts to testify to Freeman’s mental incapacity. However, he was found guilty. On appeal, the New York Supreme Court determined that the trial court erred in its jury instructions. The jurors were given a single criterion to determine insanity: whether the defendant had the capacity to distinguish between right and wrong. The Supreme Court acknowledged the need for the insanity defense as a humane policy but held that the trial court’s definition was overly broad – if it were adopted, the defense would include “insanity of any form, however partial and limited it may be.” The state court cited the M'Naghten Rule as the appropriate test for an insanity defense. It reversed the conviction and ordered a new trial, but Freeman died shortly afterwards. In a postmortem medical examination, his brain pathology was found to be consistent with insanity.
For more detail about Freeman, the murder, and his famous defense lawyer William Seward, see:
- Kenneth J. Weiss and Neha Gupta, America's First M'Naghten Defense and the Origin of the Black Rage Syndrome, 46 J. Am. Acad. Psychiatry & L. Online 503 (2018).
- Historical Society of the New York Courts
- Legal Information Institute
More Resources [for M’Naghten Rule]
For a recent discussion of the M’Naghten Rule, see the 2020 United States Supreme court case, Kahler v. Kansas, 140 S. Ct. 1021, 1046, 206 L. Ed. 2d 312 (2020), and Justice Breyer’s dissent excerpted below. The majority held that due process does not require that Kansas adopt an insanity test turning on a defendant's ability to recognize that his crime was morally wrong. Both the majority and dissent discuss the evolution of the defense from English sources and the dissent surveys versions of the insanity defense that have been adopted in jurisdictions across the United States:
Today, 45 States, the Federal Government, and the District of Columbia continue to recognize an insanity defense that retains some inquiry into the blameworthiness of the accused. Seventeen States and the Federal Government use variants of the M'Naghten test, with its alternative cognitive and moral incapacity prongs. Three States have adopted M'Naghten plus the volitional test. Ten States recognize a defense based on moral incapacity alone. Thirteen States and the District of Columbia have adopted variants of the Model Penal Code test, which combines volitional incapacity with an expanded version of moral incapacity. See Appendix, infra. New Hampshire alone continues to use the “product” test, asking whether “a mental disease or defect caused the charged conduct.” State v. Fichera, 153 N.H. 588, 593, 903 A.2d 1030, 1035 (2006). This broad test encompasses “ ‘whether the defendant knew the difference between right and wrong and whether the defendant acted impulsively,’ ” as well as “ ‘whether the defendant was suffering from delusions or hallucinations.’ ” State v. Cegelis, 138 N.H. 249, 255, 638 A.2d 783, 786 (1994). And North Dakota uses a unique formulation that asks whether the defendant “lacks substantial capacity to comprehend the harmful nature or consequences of the conduct, or the conduct is the result of a loss or serious distortion of the individual's capacity to recognize reality.” [13]
13) Kahler v. Kansas, 140 S. Ct. 1021, 1046, 206 L. Ed. 2d 312 (2020) (The dissent also contains an APPENDIX which gives excerpts from each jurisdiction’s insanity rule whether from a statute or court case). Return to text
Sources and Other Interesting Reads
- West, D. J. (Donald J., & Walk, A. (1977). Daniel McNaughton : his trial and the aftermath. Headley for the “British Journal of psychiatry.”
- J. Thomas Dalby, The Case of Daniel McNaughton: Let’s Get the Story Straight. 27 Am. J. Forensic Psychiatry 17 (2006).
- Jennifer Yu, Without the Forbidden Fruit: Returning to the Wild Beast Test, 30 Cornell J.L. & Pub. Pol'y 819 (2021).
- T.V. Asokan, Daniel McNaughton (1813-1865), 49 Indian J. Psychiatry 223 (2007)
10) Homer D. Crotty, The History of Insanity as a Defence to Crime in English Criminal Law, 12 CALIF. L. REV. 105, 116-117 (1924); See Rex v. Hadfield, 27 How. St. Tr. 1281 (K.B. 1800). Return to text
11) Simon Barber, R v Earl Ferrers: The Trial That Saved England From Revolution, VICTORIA UNIVERSITY OF WELLINGTON (2017). See Rex v. Lord Ferrers, 19 How. St. Tr. 885 (H.L. 1760). Return to text