My Law Tutor

R v McNaughten – M’Naghten

March 07, 2024
Micheal James

Jurisdiction / Tag(s): UK Law

Introduction to R v McNaughten – M’Naghten:

R v McNaughten, commonly known as M’Naghten’s Case, stands as a cornerstone in criminal law jurisprudence, particularly concerning the insanity defense. This case, which took place in the 19th century, continues to influence legal proceedings worldwide and remains pivotal in determining criminal responsibility in cases involving mental illness. The central legal issue in this case revolves around the establishment of the M’Naghten Rule, which sets forth criteria for determining whether a defendant is legally insane at the time of committing a crime.


In 1843, Daniel M’Naghten, a Scottish woodcutter, attempted to assassinate the British Prime Minister, Sir Robert Peel, under the delusion that Peel was conspiring against him. M’Naghten mistakenly killed Peel’s secretary, Edward Drummond, instead. Subsequently, M’Naghten was charged with murder, leading to a trial that would profoundly impact the legal landscape.

Legal Issues:

The primary legal issue in R v McNaughten pertains to the defendant’s mental state at the time of the offense and whether he can be held criminally responsible for his actions. The case raised questions about the understanding of insanity in criminal law and the criteria for determining a defendant’s mental capacity to commit a crime.

Facts of the Case:

During the trial, evidence was presented to establish M’Naghten’s mental state at the time of the assassination attempt. Witnesses testified about M’Naghten’s history of mental illness and delusional beliefs. Expert psychiatric opinions were also solicited to evaluate M’Naghten’s mental condition.

Trial Proceedings:

The trial proceedings involved meticulous examination of witnesses, including medical experts, who provided insights into M’Naghten’s mental health and his ability to understand the nature and consequences of his actions at the time of the offense.

Arguments Presented:

The prosecution argued that M’Naghten’s actions were premeditated and deliberate, indicating a sound mind and criminal intent. In contrast, the defense contended that M’Naghten suffered from mental illness, which rendered him incapable of understanding the nature and wrongfulness of his actions.

Court’s Decision:

After deliberation, the court rendered its decision, finding M’Naghten not guilty by reason of insanity. The court established the M’Naghten Rule, which stipulates that a defendant can be found not guilty by reason of insanity if, at the time of committing the offense, they were suffering from a mental disorder that rendered them incapable of understanding the nature and consequences of their actions or distinguishing right from wrong.

Legal Precedents and Significance:

R v McNaughten established a significant legal precedent regarding the insanity defense and continues to serve as a guiding principle in determining criminal responsibility. The M’Naghten Rule has been adopted in various jurisdictions worldwide and has shaped the understanding of mental illness in criminal law.

Impact and Implications:

The case’s impact extends beyond its immediate context, influencing subsequent legal developments and discussions surrounding mental health and criminal justice. It underscores the importance of considering mental illness in criminal proceedings and ensuring fair treatment for individuals with mental disorders.


In conclusion, R v McNaughten (M’Naghten) remains a landmark case in criminal law, setting forth fundamental principles regarding the insanity defense and criminal responsibility. Through its establishment of the M’Naghten Rule, the case has left an indelible mark on legal proceedings worldwide, emphasizing the need for a nuanced understanding of mental illness within the criminal justice system.

Why Choose Us:

Seeking Online Law Dissertation Help can greatly aid students in navigating the complexities of legal research and writing. These services offer tailored assistance, including topic selection, literature review, data analysis, and dissertation composition. By leveraging expert guidance, students can refine their research methodologies, enhance their critical analysis skills, and produce high-quality dissertations that contribute to the legal academic discourse. Online Law Dissertation Help ensures that students receive comprehensive support throughout the dissertation process, from conceptualization to final submission, empowering them to excel in their academic pursuits and make meaningful contributions to the field of law.

Cite This Work

Select a referencing style to export a reference for this article:

All Answers ltd, 'R v McNaughten – M’Naghten' (, ) <> accessed 24 July 2024
My, Law, Tutor. ( ). R v McNaughten – M’Naghten. Retrieved from
"R v McNaughten – M’Naghten." . All Answers Ltd. 07 2024 <>.
"R v McNaughten – M’Naghten." MyLawTutor., . Web. 24 July 2024. <>.
MyLawTutor. . R v McNaughten – M’Naghten. [online]. Available from: [Accessed 24 July 2024].
MyLawTutor. R v McNaughten – M’Naghten [Internet]. . [Accessed 24 July 2024]; Available from:
<ref>{{cite web|last=Tutor |first=MyLaw |url= |title=R v McNaughten – M’Naghten | |date= |accessdate=24 July 2024 |location=UK, USA}}</ref>

Related Cases

Haystead v DPP

UK Law . Last modified: July 20, 2024

Introduction to Haystead v DPP: Haystead v DPP is a notable case in criminal law that grapples with the legal complexities surrounding the concept of criminal liability for omissions. This case study aims to provide a comprehensive analysis of Haystead v DPP, examining its background, legal issues, court proceedings, judgment, impact, controversies, and significance within […]

Simpkins v Pays – 1955

UK Law . Last modified: March 4, 2024

Introduction to Simpkins v Pays – 1955 In 1955, a seemingly ordinary newspaper competition became the springboard for a landmark legal battle in England. Simpkins v Pays, decided in the Chester Assizes, centered around three ladies – Ms. Simpkins, her landlady Ms. Pays, and Ms. Pays’ granddaughter – and their informal agreement to share the […]

Bernstein v Skyviews – 1978

UK Law . Last modified: July 20, 2024

Introduction to Bernstein v Skyviews: Bernstein v Skyviews – 1978 remains a pivotal case in property law, particularly regarding aerial photography and privacy rights. This case involved a dispute between Bernstein, the plaintiff, and Skyviews, the defendant, over the unauthorized aerial photography of Bernstein’s property. It raised significant questions about property rights and the limits […]

Storer v MCC 1974

UK Law . Last modified: March 5, 2024

Introduction to Storer v MCC: The 1974 case of Storer v MCC, decided by the Court of Appeal, stands as a pivotal decision in English contract law, addressing the validity of agreements with unsigned documents and incomplete terms. The case centered around Mr. Storer’s claim that a contract existed for him to purchase a property […]

Caunce v Caunce [1969]

UK Law . Last modified: July 20, 2024

 Introduction to Caunce v Caunce [1969] Caunce v Caunce (1969) stands as a significant, albeit controversial, case in English property law. It grappled with the rights of a wife who contributed financially to a matrimonial home but lacked legal ownership due to outdated legal principles. This case study delves into the facts, legal issues, […]

Pitts v Hunt – 1991

UK Law . Last modified: March 7, 2024

Introduction to Pitts v Hunt: Pitts v Hunt – 1991 stands as a pivotal case in legal jurisprudence, offering valuable insights into the complexities of contract law and negligence. This case study delves into the background, legal issues, arguments presented, procedural history, analysis, decision, and implications of this landmark litigation. By examining the interplay between […]

go to top