The concept of responsibility connects with our most fundamental convictions about human nature and dignity and everyday experience of guilt and innocence and blame and punishment. Punishing a person, who is not responsible for the crime, is a violation of the basic human rights and fundamental rights under the Constitution of India. It also brings the due process of law, if that person is not in a position to defend himself in the court of law, evoking the principle of natural justice. The affirmative defence of legal insanity applies to this fundamental principle by excusing those mentally disordered offenders whose disorder deprived them of rational understanding of their conduct at the time of the crime. Hence, it is generally admitted that incapacity to commit crimes exempts the individual from punishment. This is recognized by the legislation of most of the civilized nations. Even in India, Section 84 of Indian Penal Code (IPC) deals with the “act of a person of unsound mind” and discusses insanity defence. However, in the recent past, some of the U.S. states (such as Montana, Idaho, Kansas, and Utah) have banned insanity defence. This issue has raised serious debate among medical, psychology and law professionals across the world.

Very little research has been done on this topic in India, however, there are few studies on exploring the clinical picture of the patients in prison. A landmark study in the forensic psychiatry of Indian setting occurred in 2011, in which 5024 prisoners were assessed on semi-structured interview schedule reported that 4002 (79.6%) individuals could be diagnosed as having a diagnosis of either mental illness or substance use. After excluding substance abuse, 1389 (27.6%) prisoners still had a diagnosable mental disorder. Another study from India portrays a very gloomy picture of patients in forensic psychiatry settings and advocate for there is a need to streamline the procedure of referral, diagnosis, treatment, and certification. To address this issue of streamlining the process of evaluation of insanity defence and certification, this article focuses on semi-structured assessment in the Indian context based on landmark Supreme Court decisions. In addition, it will also present a model for evaluating a defendant’s mental status examination and briefly discuss the legal standards and procedures for the assessment of insanity defence evaluations.

INSANITY DEFENCE: A LOOPHOLE FOR CRIMINALS | Historical, Medical, Legal perspective


The insanity defence has been in existence for many centuries; however, it took a legal position only since the last three centuries. There were various tests used to declare a person legally insane such as Wild Beast test, The Insane Delusion test, and “test of capacity to distinguish between right and wrong. These three tests laid the foundation for the landmark Mc Naughten rule.

In 1843, Daniel Mc Naughten, a wood-turner from Glasgow, shot and killed Edward Drummond mistaking him for Sir Robert Peel. Mc Naughten believed that he was persecuted by the Tories, and evidence was brought to show that he had been totally deluded on this subject for some time. His state of mind was apparent from the outset when he had to be coaxed, and finally tricked, into pleading “not guilty.” After hearing seven medical witnesses testify that he was completely insane, the judge stopped the trial, the jury brought in the special verdict without summing up and without retiring, and Mc Naughten was forcibly committed to the Bethlem Hospital. Immediately thereafter, five propositions were drawn which were called Mc Naughten rules.

This Mc Naughten rule became a legendary precedent for the law concerning the defence of insanity. Even, in India, insanity defence law, Section 84 IPC is solely based on the Mc Naughten rules. Since it is drafted, no changes have been made. However, in 1971, there was an attempt by the Law Commission of India to revisit Section 84 in their 42nd report, but no changes were made.

Section 84 of IPC deals with the “act of a person of unsound mind. “Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law.”

On analysis of Section 84 IPC, the following essential ingredients can be listed. For the sake of easy understanding, Section 84 IPC can be divided into two broad categories of, major criteria (medical requirement of mental illness) and minor criteria (loss of reasoning requirement). Major criteria (mental illness requirement) mean the person must be suffering from mental illness during the commission of the act. Minor criteria (loss of reasoning requirement) mean the person is:

  1. Incapable of knowing the nature of the act or
  2. Incapable of knowing his act is wrong or
  3. Incapable of knowing it is contrary to law.

Both major (mental illness) and minor (loss of reasoning) criteria constitute legal insanity.

Section 84 IPC, clearly embodies a fundamental maxim of criminal jurisprudence that is, (a) “Actus nonfacit reum nisi mens sit rea” (an act does not constitute guilt unless done with a guilty intention) and (b) “Furiosi nulla voluntas est” (a person with mental illness has no free will). This means that an act does not constitute a crime unless it is done with a guilty intention called “mens rea.” Hence, Section 84 IPC fastens no culpability on persons with mental illness because they can have no rational thinking or the necessary guilty intent.


Modern criminal law is based on the belief that humans are morally responsible and not harm causing agents. To be held criminally responsible, two essential elements have to be proven, beyond a reasonable doubt, (a) the person committed the act (actus reus) (b) in doing so, the person acted with his or her own free will, intentionally and for rational reasons (mens rea).

Psychiatrists may be asked to assist the court in determining whether certain mental disorders affected a person’s ability to form the intent necessary to make that person legally culpable.

Medical insanity versus legal insanity

Section 84 lays down the legal test of responsibility in cases of alleged crime done by a person with mental illness. There is no definition of “unsoundness of mind” in the IPC. The courts have, however, mainly treated this expression as equivalent to insanity. But the term “insanity” itself has no precise definition, carries a different meaning in different contexts and describes varying degrees of mental disorders. Every person who is mentally ill is not ipso facto exempted from criminal responsibility. A distinction is to be made between legal insanity and medical insanity. A court is concerned with legal insanity, and not with medical insanity. Any person, who is suffering from any kind of mental illness is called “medical insanity,” however “legal insanity” means, a person suffering from mental illness should also have a loss of reasoning power. The term legal insanity also refers to the “mental state” of a person at the time of committing a crime and nothing else. This is purely a legal concept and is unrelated to the various psychiatric diagnoses.

In simple words, legal insanity means, at the time of the commission of the act, the person should be suffering from mental illness and also have a loss of reasoning power. This issue is clearly depicted in Section 84 IPC as that person is incapable of knowing:

  1. The nature of the act, or
  2. That he is doing what is either wrong or
  3. Contrary to law.

Mere abnormality of mind or partial delusion, irresistible impulse or compulsive behaviour of a psychopath affords no protection under Section 84 IPC.

In one of the landmark decisions, in the case of Surendra Mishra versus state of Jharkhand, the Apex Court has stated that an accused who seeks exoneration from liability of an act under Section 84 of the IPC is to prove legal insanity and not medical insanity. Further, it also said that the expression “unsoundness of mind” has not been defined in the IPC, and it has mainly been treated as equivalent to insanity. But the term insanity carries a different meaning in different contexts and describes varying degrees of mental disorders. Every person who is suffering from mental illness is not exempted from criminal liability. The mere fact that the accused is conceited, odd, irascible, and his brain is not quite all right, or that the physical and mental ailments from which he suffered had rendered his intellect weak and affected his emotions or indulges in certain unusual acts, or had fits of insanity at short intervals or that he was subject to epileptic fits and there was abnormal behaviour or the behaviour is queer are not sufficient to attract the application of Section 84 of the IPC.

The Apex Court in its judgment reported that though accused suffered from certain mental instability of mind even before and after the incident but from that one cannot infer on a balance of preponderance of probabilities that the appellant at the time of the commission of the offence did not know the nature of his act; that it was either wrong or contrary to law, hence rejected an insanity defence. In a similar case, despite having a medical history of insanity proved by evidence in court, the court convicted the accused based on his subsequent conduct viz., his act of concealing the weapon, bolting the door to prevent arrest and absconding thereafter as the said acts were held by the court to be a display of consciousness of the guilt.

INSANITY DEFENCE: A LOOPHOLE FOR CRIMINALS | Historical, Medical, Legal perspective

Burden of proof in insanity defense

Under the law, every man is presumed to be sane and assumed to possess a sufficient degree of reason to be responsible for his acts unless the contrary is proved. Every person is presumed to know the natural consequences of his act. Similarly, every person is also presumed to know the law. The prosecution does not have to establish these facts.

In the insanity defence, there are two aspects of proving an offence, which are as follows:

  1. Commission of crime and
  2. Insanity defence.

The burden of proving the commission of an offense is always on the prosecution, and that never shifts. The prosecution has to prove the same beyond a reasonable doubt. However, the onus of proving the existence of circumstances (Section 84 IPC) for insanity defence would be on the accused (Section 105 of the Evidence Act) and the court shall presume the absence of such circumstances. The accused has to prove by placing material before the court such as expert evidence, oral and other documentary evidence, presumptions, admissions or even the prosecution evidence, satisfying that he was incapable of knowing the nature of the act or of knowing that what he was doing was either wrong or contrary to law.

The Supreme Court has ascertained that the crucial point of time at which unsoundness of mind should be established is the time when the crime is actually committed and the burden of proving this, lies on the appellant for claiming the benefit of the Section 84 provision.

In Dahyabhai Chhaganbhai Thakker versus state of Gujarat, this court has held that even if the accused was not able to establish conclusively that he was insane at the time he committed the offense, the evidence placed before the court may raise a reasonable doubt in the mind of the court as regards one or more of the ingredients of the offense, including mens rea of the accused and in that case the court, would be entitled to acquit the accused on the ground that the general burden of proof resting on the prosecution was not discharged. Though the burden is on the accused, he is not required to prove the same beyond all reasonable doubt, but merely satisfy the preponderance of probabilities. The burden of proof casted upon him is no higher than that rests upon a party to civil proceedings.

Plea of insanity

The onus of proving unsoundness of mind is on the accused, hence the plea of insanity should be taken by the accused or by his lawyer or his family members or previous history of insanity is revealed, it is the duty of an honest investigating officer to subject the accused to a medical examination and place that evidence before the court and if this is not done, it creates a serious infirmity in the prosecution case and the benefit of doubt has to be given to the accused. Hence, the plea of insanity should be taken during the investigation or during the trial in the lower court not during the appeal to the higher court.

How Psychiatrists Get Involved in Cases that Involve the Insanity Defence

One way that psychiatrists get involved in insanity cases is through their patients. This would necessitate the unfortunate event where a patient is involved in a criminal matter. The patient and his or her counsel choose to make his or her state of mind at the time of the alleged incident an issue and you, as the treating physician, are called to testify.

The other common way psychiatrists end up playing a role in these cases is as a consultant who is serving to evaluate the individual as well as the circumstances of the crime. In such a case, you are actually seeing the person under a court order or at the request of one of the attorneys, and it is quite different than seeing a patient, especially when issues such as confidentiality come up.

What it Means When Someone is Found Not Guilty by Reason of Insanity

When a defendant is found not guilty by reason of insanity it does not mean he or she necessarily goes free. Commonly, states have requirements for treatment or institutionalization after such a finding. Some states require such confinement for the length of time the person would have received if convicted as a minimum, so he or she may end up spending more time confined than if he or she did not raise such a defence. Like other areas of the law, this varies from state to state.


Psychiatrists may be asked to assist the court in determining whether certain mental disorders affected a person’s ability to form the intent necessary to make that person legally culpable. The medical discipline describes the patient’s mental status on a continuum that ranges from extremely ill to completely healthy. However, the legal language is clearly categorical in nature, either criminally responsible or not responsible. While a psychiatrist is concerned with medical treatment of individual patients, courts are concerned with the protection of the society from the possible dangers from these patients. Psychiatrist needs to understand that it is not only the fact that the person is suffering from mental illness but it is the totality of the circumstances seen in the light of the evidence on record to prove that the person was also unable to appreciate the nature of the act or wrongdoing or that it was contrary to the law is appreciated in the court of law for insanity defence. Above all that Forensic Psychiatric Informal Training and Clinical Services Providing Centers are few in number across the country. To provide fair and speedy trial, forensic psychiatry needs to be given utmost importance.

Ria Tandon

Ria Tandon is a freelancer writer and an aspiring lawyer. She is currently pursuing her fourth year of the five year integrated course from New Law College, Bharati Vidyapeeth Deemed to be University Pune. Her main areas of work includes writing blogs, articles, research paper to influence people in some or the other way, since internet is already a place where most of the people gets news and awareness from and the industry will be getting bigger and bigger by the time she graduates from the college.
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