Criminal Commitment and the Insanity Defense Explained
This paper examines the legal concept of criminal insanity and how it differs from both colloquial and clinical definitions of mental illness. It traces the historical origins of the insanity defense from the 1843 M'Naghten case through subsequent refinements such as the Durham rule and the American Law Institute standard. The paper also distinguishes between the insanity defense and competency to stand trial, addresses civil and criminal commitment procedures, and discusses the rights of the involuntarily committed. Throughout, it challenges common public misconceptions about how frequently and successfully the insanity defense is used in American courts.
- Introduction: Legal vs. Colloquial Insanity: Legal insanity differs from everyday or clinical definitions
- The Insanity Defense Defined: Formal definition and distinction from competency
- Historical Origins: The M'Naghten Rule: 1843 case establishes the right-wrong test
- Refinements to the Insanity Standard: Durham rule and ALI standard update M'Naghten
- Public Controversy and Criminal Commitment: Low usage rates and consequences of insanity acquittals
- Civil Commitment and the Rights of the Mentally Ill: Involuntary commitment procedures and patient rights
- Conclusion: Defense remains necessary despite public confusion
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What makes this paper effective
- The paper grounds abstract legal concepts in concrete, accessible examples — such as postpartum psychosis and the Mafia boss with dementia — which make the distinctions between competency and insanity immediately understandable.
- It follows a clear historical narrative arc, moving from the origins of the M'Naghten rule through subsequent legal reforms, giving readers a sense of how the law has evolved rather than presenting static definitions.
- The paper addresses and dismantles a common public misconception (that the insanity defense is widely abused) using specific statistics, which strengthens its credibility.
Key academic technique demonstrated
The paper effectively uses compare-and-contrast reasoning to draw precise legal distinctions — for example, differentiating the insanity defense from competency to stand trial, and the M'Naghten "right-wrong" test from the Durham rule. This technique allows the writer to clarify a complex, often misunderstood area of law without oversimplifying it.
Structure breakdown
The paper opens by identifying the gap between public perception and legal reality, then defines the insanity defense formally. It proceeds chronologically through the M'Naghten and Durham rules before shifting to the social and political controversies surrounding commitment. It closes by addressing civil commitment rights and a brief conclusion affirming the defense's necessity.
Introduction: Legal vs. Colloquial Insanity
When a defendant is found not guilty by reason of insanity, the public often cries out in outrage. However, some people are found guilty and not criminally insane despite committing barbarous actions that only an apparently insane individual would commit. The reason for this apparent contradiction is that the legal definition of insanity differs from both the colloquial definition (as in: "you're crazy!") and the clinical, psychological definition. A person can be mentally unbalanced yet still able to differentiate right from wrong, and thus legally sane.
Although it can be difficult to determine criminal insanity in a justice system "largely designed to weigh facts and evidence," the insanity defense is largely considered a necessary mercy (Martin 1998). State of mind is a factor when considering many crimes and punishments. Additionally, a criminal punishment is an ineffective deterrent for an individual unable to discern right from wrong. If someone believes, because of insanity, that they have killed a devil or a terrorist, jail time will not cause them to repent of their ways. The nature of the defendant and his or her state of mind is always questioned in criminal cases, even on a basic level of humanity — "a child who accidentally starts a fire shouldn't be treated as an arsonist," for example (Martin 1998).
The Insanity Defense Defined
The insanity defense is "a plea that defendants are not guilty because they lacked the mental capacity to realize that they committed a wrong or appreciate why it was wrong" (Martin 1998). It is different from the question of whether a defendant is competent to stand trial. The insanity defense concerns the defendant's state of mind at the time he or she was committing the crime.
For example, a woman could have committed a crime while suffering from postpartum psychosis but, because she has since recovered, she is competent to stand trial while still pleading the insanity defense. In contrast, a Mafia boss could be incompetent to stand trial because of dementia, yet not plead insanity as a defense regarding the criminal activity he allegedly directed during his mentally competent youth (Martin 1998).
Historical Origins: The M'Naghten Rule
The definition of criminal insanity originated in British common law. In 1843, Daniel M'Naghten, a woodworker, believed he was the target of a conspiracy involving the Pope and British Prime Minister Robert Peel. "M'Naghten traveled to 10 Downing Street to ambush Peel, but mistakenly shot and killed Peel's secretary. During the ensuing trial, several psychiatrists testified M'Naghten was delusional. A jury agreed, declaring him not guilty by reason of insanity. The public howled in outrage and, a year later, a panel of British judges set forth the legal standard that has been used for 150 years" (Martin 1998).
The M'Naghten rule holds that defendants may be acquitted only if they labored "under such defect of reason from disease of the mind" as to not realize what they were doing or why it was a crime. Some call it the "right-wrong" test (Martin 1998). For example, a mother might claim insanity on the grounds that she believed she was saving her children by killing them, as a result of postpartum psychosis.
Conclusion
In reviewing these various aspects of the insanity defense, it becomes clear why the public is so often confused by the defense. Even legal professionals find it difficult to determine what constitutes a defendant's state of mind at a particular time. Defining what any person — particularly a mentally unbalanced person — is thinking continues to challenge legal scholars and the court system alike. However, doing away with the insanity defense, given the injustices this would produce, would be, by any definition of the word, insane.
Works Cited
Durham rule. (2009). Law Dictionary. Retrieved March 5, 2009, from
Legal issues. (2009). Retrieved March 5, 2009, from
Martin, John P. (1998, February 27). The insanity defense: A closer look. Washingtonpost.com. Retrieved March 5, 2009, from http://www.washingtonpost.com/wp-srv/local/longterm/aron/qa227.htm
Your rights under involuntary commitment. (1997). Advocacy, Inc. Retrieved March 5, 2009, from
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