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Vishalakshi, Faculty of Law, Banaras Hindu University.

Date: 12.06.2021



Criminal Justice System gives fair and equal chance to both victims and the accused to prove their point and it not only provides provisions for punishment of accused but also allows them to take defence under certain provisions. One such defense primarily mostly used in criminal prosecution is the Defense of Insanity. This insanity defence is an assumption that during the commission of crime, the defendant was suffering from severe mental illness, therefore he was not capable for knowing the nature of crime that he had done at that time. Law holds a person guilty of any crime if he has done that with wish and free will. Criminal Law is based on the principle of “Actus Non Facit Ream Nisi Mens Sit Rea”  which means the physical act does not make a person guilty, the mental component in the form of evil intent is equally important and  “Furiosi nulla voluntas est” which means a person with mental illness has no free will. Therefore, for making a person liable one must do some guilty act and he must have a guilty mind for doing the offence. But if a person is insane, he is incapable of forming rationale decision as to what is good or contrary to law and when a person cannot decide what is right and what is wrong, in law it is considered that in such situation a person cannot have a guilty mind and hence he should be acquitted. So, this plea of unsoundness of mind or insanity saves the person from capital punishment.

A person who suffers from mental illness or disorder due to various psycological factors, anxiety, depression, or suffers from mental illness since its birth is considered to be insane. But only proving mental disorder is not sufficient to prove insanity as a proof. The insane person has to supply the court with proper evidence similar to that of “preponderance of the evidence” as in the civil case  which claims him to be insane. The burden of proving insanity lies on the defence.

But the insanity as defence has always been in question, because many criminals take undue advantage of insanity as a defense and plead false insanity in order to get rescued from being punished during their trials. In criminal justice system the insanity defence is generally taken as an excuse rather being a justification of facts and the crime. Hence, it is used as a loophole in the judicial system in order to escape from the punishment during the trial.


The concept of insanity is in existance since ages and ancient Greece and Rome has also been found using this defence in their courts. But it was first recognised as defence to criminal charges in 1581 by English Legal Treatise when it was stated that “If a madman or a natural fool, or a lunatic in the time of his lunacy” kills someone, they cannot be held accountable. The British Courts developed different tests such as “wild beast” test in 18th century, in which the defendants were not to be convicted if they understood the crime no better than “an infant, a brute, or a wild beast.”1 This test led the first formal basis for law of insanity and was followed by various other tests which were also deduced to check if a person is legally insane such as the Insane Delusion test2, the Good and Evil test wherein it was to be seen that the person who had committed some crime has the ability to distinguish between good and evil.3 These three tests were the early laws relating to Insanity Defence and laid the foundation for the landmark Mc-Naughton Test.

The British Courts in R v. McNaughton4, devised the McNaughton’s Test which formed the basis of modern-day Insanity Law and is also the basis of Section 84 of the Indian Penal Code. McNaughton who was the accused in this case killed Edward Drummond mistaking him for some other person. He took the plea of insanity that his state of mind was not sane and hence, the court acquitted him. This created a huge uproar and after this judgment in 1843, there was a discussion in the House of Lords, where a five-point proposition was made. These five propositions were construed as the McNaughton’s rules. These propositions became precedent for the law concerning the defence of insanity. The rules emphasized the observation of “understandability” of an accused in a case where he/she has done something wrong. It is a test of knowing what is right and wrong.

The propositions were as follows:

1.     Every convict shall be presumed to be sane at the time of commission of offence until the contrary is proven.

2.     If at the time of commission of offence, the insane person have the knowledge of what he/she is doing, then he/she would be liable for punishment.

3.     To take the plea of insanity the accused person should not be in a position to know the nature and consequence of his/her act.

4.     The delusions to which the accused is suffering should be real.

5.     The Jury in English law would be held responsible for deciding if someone is insane or not.


Indian Law also gives a person the defence of insanity under section 845 of Indian Penal Code, 1860 which is primarily based on the McNaughton’s rules. Section 84 of IPC states that nothing is an offence which is done by a person who at the time of doing it, by the reason of unsoundness of mind, was incapable of understanding the nature and consequence of the act he/she is doing and that the act is prohibited by law. Hence, Section 84 of IPC affixes no culpability on persons with mental illness because they can have no rational thinking or the necessary guilty intent.

Therefore, section 84 of the IPC can be broadily divided into two main categories:

1.   MAJOR CRITERIA: It consists of the medical and mental requirement of the ill person which means a person should be suffering from some mental illness or disorder at the time of the commission of the offense.

2.   MINOR CRITERIA:  It consists of loss of knowledge that a person at the time of the commission of an offense is incapable of knowing nature, wrongful acts, and that his/her actions are contrary to the law.


Section 84 of Indian Penal Code,1860 lays down the legal test for mental illness but the statute fails to define the term ‘unsoundness of mind’ or ‘insanity’ term has nowhere been precisely defined in the code. Medical insanity is different from legal insanity and therefore, who suffers from mental illness is not always exempted from the punishment because the courts are concerned with legal insanity and not the mental insanity.

Differentiation in simple term could be the disease of mind is legal insanity where functioning i.e., quality of brain is affected and medical insanity could be disease of brain which is the malformation of brain such as in size or weight. When a person suffers from legal insanity, he/she losses his/her reasoning power at the time of commission of crime. This may also be called as ’defect of reason’. For insanity to qualify for legal insanity any one the 3 essentials of Section 84 as mentioned earlier must be fulfilled and only then the accused can seek a defence by way of insanity.


In Bapu @ Gajraj Singh vs State of Rajasthan6, Hon’ble Supreme Court held that Mere abnormality of mind or partial delusion, irresistible impulse or compulsive behaviour of a psychopath affords no protection under Section 84 IPC.

Hon’ble Supreme Court in Surendra Mishra v. State of Jharkhand7, held that Section 84 IPC is only for legal insanity and not medical insanity and therefore a person suffering from mental illness is not exempted from criminal liability.


A person who is suffering from unsoundness of mind is similar to a child who does not know about his/her acts and the consequences that will follow thereof. Hence, convicting that person who himself does not know what he is actually doing would be against the morality. Therefore, this defence is life-giver for those who are suffering from mental illness. The defence does not provide for capital punishment. In insanity, the person accepts the act committed by him but although confessed, is incapable of forming an understanding about the gravity of what he has done and therefore, harsh punishment such as rigorous imprisonment or death penalty would be unjustifiable.


This defense has become the easiest way to escape from punishment and now-a-days it is used by the sane accused as well. Insanity is used as a false ground by the accused as it is very difficult to examine whether the person was of sound mind or unsound mind at the time when the crime was committed. This way the case depends upon the prudence of the judge and in one way or the other the law losses its essential purpose. The plea can be abused by sane persons. Though guaranteed as a privileged defense for the insane by the judicial system many sane people take undue advantage and abuse this privileged defense. It is therefore because of this misuse several countries like as Germany, Argentina, Thailand and many counties in England have abolished this defence.

Also, one of the major drawbacks of this defence is that the burden of proving the insanity lies on the accused and is  very difficult to prove this defence. Medical insanity is easier to prove as compared to legal insanity which is a very big challenge because the party has to provide concrete evidence to prove the insanity. It is extremely difficult to fulfil the essentials of Section 84 IPC to show legal insanity and it is so because of this difficulty many legitimate cases is charged and punished.


The insanity defence is guaranteed by the Indian Legal Statute to protect the insane person who by the reason of unsoundness of mind and unable to figure out the difference between right and wrong. Insane persons by using this defense would get very lesser punishment or even may get completely absolved from punishment. But for that purpose, the insane man has to prove that they are insane and mentally unsound in the eyes of law by producing fair evidences which declares them unsound or incapable of having knowledge about their actions and its consequences.

But this defense is misused by the criminals of sane mind who have absolute knowledge about their actions and the consequences and who can differentiate between the right and contrary to law to get acquittal by the law for the crime they commit. The criminals misuse this defense when they commit heinous crimes like rape, murder, abduction etc., which has strict and rigorous punishments such as capital punishments.

The offenders who are of sound mind in their full capacity of knowledge commits offence and they plead insane in-front of the court because they think they can easily get away with the punishment after committing some heinous crime if they will take insanity defense. And the most shocking part is that, at times these people even manage to get this defense by proving themselves insane. They manipulate the reports, threaten the doctors and prove their mind unsound. One major reason for this could be the corruption and poverty which are root evil of this nation.  The powerful man sitting in their AC chambers mishandle their powers and abuse the judicial system at ground level. Sometimes even the evidences and witnesses are manipulated by the offenders and false evidences are produced before the court with help of political hands and financial aid in this country.

Insanity has become a loophole for criminals. Proving insanity is not an easy task and it takes lots of time to satisfy the mind of judges that the person is suffering from unsoundness of mind, which causes delay in justice delivery system. This delay leads to abuse of judiciary by the hand of accused. Criminals who willingly abuse the justice delivery system by manipulating the statute are well acquainted with the actions and consequences their actions follow, they have full knowledge and motive in doing what they have done such as injury, grevious hurt, or murder or rape and hence perform the act having intention to do so. The defense of insanity gets them easy acquittal and possibly no punishment is charged on them, because the condition of mind of a person can be changed on piece of paper but predicting whether the person is sane or not is very difficult. After proving all the evidences in the court, it is upon the discretion of judge whether to pass judgement in the favour of the accused person or against him and whether he should be punished or not?

The criminals in most of the cases are so powerful due to their political linkups and financial strength that they threaten judges and even bribe them in order to escape from the punishment. Some criminals are so eminently dangerous threat they take away the lives of people who serve to the legal system with proper and lean motive. It is also seen that these people and their family members in some cases end up loosing their goodwill and reputation in the society. The offenders use this defense without and fear and think that now they are free and no one can do anything to them. They think justice lies below their feet and legal system is sleeping. Even after having so many amendments and strict laws due to some loopholes in the judicial mechanism, the criminals manage to escape from crimes by using this insanity defense which is the biggest loophole in the court of law.


As it can be seen that insanity defense has become a loophole for the criminals and a popular defense to abscond from the crime. It is next to impossible to prove the mental stage of a person at the time of commission of a crime hence it becomes easier for the criminals to manipulate the papers and the evidences. Law tells that medical insanity and legal insanity is different but how and what should be th exact parameter of judging a person whether he is legally insane or not, the law does not tell us about this. Insanity has not been clearly defined under section 84 so that a clear distinction should be made to decide the stage of person at the time of commission of crime. This lacuna added fuel to the fire which makes this defense loos its stark, and all that matters are word-games. What makes the situation more complicated at times is that in this defense the accused clearly accepts the commission of crime but evades from accepting the knowledge of consequences and this raises brow of any right-minded rationale person in the society. Now the remedies available to cope up with these lacunas are the formation of more straightforward laws and tests.

If we talk about the cases which are happening underground of insanity subjects are more disasters in comparison to others to some extent crime reached to the peak legal discussion or agenda in order to sustain precise judgment. Thus, there is a need to expand the scope and ambit of Section 84 of IPC, 1860 in order to avoid future occurrence of such crimes and criminals using the same as a loophole in order to be set free and avoiding any punishment for the same under the trials.


1 R. v. Arnold. 1724, 16 St.Tr.695

2 Hadfield Case. 1800, 27 St.Tr.128

Bowler’s case. 1812, 1 Collinson Lunacy 673

4 R v. McNaughton, (1843) 8 Eng. Rep. 718, 722


6 MANU/SC/7754/2007

7 (2011) 3 SCC (Cri.) 232,describes%20the%20defence%20of%20insanity.&text=This%20law%20is%20based%20upon,act%20is%20prohibited%20by%20law.

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