Section 84 of IPC, which comes under general exceptions exonerates the person who committed the act under the state of insanity. But, it is not easy to prove the insanity of the person before the court. In Dayabhai v. State of Gujarat, Supreme court laid down principles regarding the burden of proof in the context of plea of insanity.
First, it would be convenient to notice the relevant aspects of the law of the plea of insanity.
Read also- Origin of Law: Why does law Exempt lunatic person from Punishment?
1. INDIAN PENAL CODE
Section 299—Whoever causes death by doing an act with the intention of causing death, or with the intention of causing such bodily injury as is likely to cause death, or with the knowledge that he is likely by such act to cause death, commits the offence of culpable homicide.
Section 84—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.
2. NDIAN EVIDENCE ACT
Section 105–When a person is accused of any offence, the burden of proving the existence of circumstances bringing the case within any of the General Exceptions in the Indian Penal Code or within any special exception or proviso contained in any other part of the same Code, or in any law defining the offence, is upon him, and the Court shall presume the absence of such circumstances.
This section contains the words ‘prove’, ‘shall presume’. Section 4 of Indian evidence Act defines this words.
Section 4-“Shall presume“: Whenever it is directed by this Act that the Court shall presume a fact, it shall regard such facts as proved unless and until it is disproved.
“Proved”-A fact is said to be “proved” when after considering the matters before it, the Court either believes it to exist, or considers its existence so probable that a prudent man ought, under the circumstances of the particular case, to act upon the supposition that it exists.
“Disproved”-A fact is said to be disproved when, after considering the matters before it, the Court either believes that it does not exist, or considers its non-existence so probable that a prudent man ought, under the circumstances of the particular case, to act upon the supposition that it does not exist.
Section 101–Whoever desires any Court to give judgment as to any legal right or liability dependent on the existence of fact which he asserts, must prove that those facts exist. When a person is bound to prove the existence of any fact. it is said that the burden of proof lies on that person.
General burden and special burden of proof
It is a fundamental principle of criminal jurisprudence that an accused is presumed to be innocent and, therefore, the burden lies on the prosecution to prove the guilt of the accused beyond reasonable doubt.
The general burden, which is always on the prosecution and which never shifts, and the special burden that rests on the accused to make out his defence of insanity under general exceptions.
This general burden never shifts and it always rests on the prosecution. But, as s. 84 of the Indian Penal Code, being an exception, under s. 105 of the Evidence Act the burden of proving the existence of circumstances bringing the case within the said exception lies on the accused; and the court shall presume the absence of such circumstances.
To put it in other words, the accused will have to rebut the presumption that such circumstances did not exist, by placing material before the court sufficient to make it con- sider the existence of the said circumstances so probable that a prudent man would act upon them.
The accused has to satisfy the standard of a “prudent man”. If the material placed before the court. such as, oral and documentary evidence, presumptions, admissions or even the prosecution evidence, satisfies the test of “prudent man”, the accused will have discharged his burden.
BURDEN OF PROOF FOR THE PLEA OF INSANITY
In Halsbury’s Laws of England, 3rd edn., Vol. 10, at p. 288, it is stated thus: “The onus of establishing insanity is on the accused. The burden of proof upon him is no higher than which rests upon a party to civil proceedings.”
1. K.M.Nanavati v. State of Maharashtra
Supreme Court in K. M. Nanavati v. State of Maharashtra had to consider the question of burden of proof in the context of a defence based on the exception embodied in s. 80 of the Indian Penal Code.
“The alleged conflict between the general burden which lies on the prosecution and the special burden imposed on the accused under s. 105 of the Evidence Act is more imaginary than real. Indeed, there is no conflict at all. There may arise three different situations:
- A statute may throw the burden of proof of all or some of the ingredients of an offence on the accused: (see ss. 4 and 5 of the Prevention of Corruption Act).
- The special burden may not touch the ingredients of the offence, but only the protection given on the assumption of the proof of the said ingredients: (see ss. 77, 78, 79, 81 and 88 of the Indian Penal Code).
- It may relate to an exception, some of the many circumstances required to attract the exception, if proved, affecting the proof of all or some of the ingredients of the offence: (see s. 80 of the Indian Penal Code)
In the third case, though the burden lies on the accused to bring his case within the exception the facts proved may not discharge the said burden, but may affect the proof of the ingredients of the offence.”
What is said of s. 80 of the Indian Penal Code will equally apply to s. 84 thereof.
2. H.M. Advocate v. Fraser
A Scottish case, H.M. Advocate v. Fraser, noticed in Glanville Williams’ “Criminal Law“, The General Part, 2nd Edn., at p. 517, pinpoints the distinction between these two categories of burden of proof.
There, a man killed his baby while he was asleep; he was dreaming that he was struggling with a wild beast. The learned author elaborates the problem thus:
“When the Crown proved that the accused had killed his baby what may be called an evidential presumption or presumption of fact arose that the killing was murder. Had no evidence been adduced for the defence the jury could have convicted of murder, and their verdict would have been upheld on appeal. The burden of adducing evidence of the delusion therefore lay on the accused. Suppose that, when all the evidence was in, the jury did not know what to make of the matter. They might suspect the accused to be inventing a tale to cover his guilt, and yet not be reasonably certain about it. In that event the accused would be entitled to an acquittal. The prosecution must prove beyond reasonable doubt not only the actus reus but the mens rea. “
3. Dahyabhai Chhaganbhai Thakker vs State of Gujarat
In this case, the supreme court laid down the principle to accept the plea of insanity. The doctrine of burden of proof in the context of the plea of insanity may be stated in the following propositions:
- The prosecution must prove beyond reasonable doubt that the accused had committed the offence with the requisite mens rea, and the burden of proving that always rests on the prosecution from the beginning to the end of the trial.
- There is a rebuttable presumption that the accused was not insane, when he committed the crime, in the sense laid down by s. 84 of the Indian Penal Code. Indian Penal Code: the accused may rebut it by placing before the court all the relevant evidence-oral, documentary or circumstantial, but the burden of proof upon him is no higher than that rests upon a party to civil proceedings.
- Even if the Accused was not able to establish conclusively that he was, insane at the time he committed the offence, the evidence placed before the court by the accused or by the prosecution may raise a reasonable doubt in the mind of the court as regards one or more of the ingredients of the offence, 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.
 1964 AIR 1563
  Supp. 1 S.C.R. 567, 597, 598
 Dahyabhai Chhaganbhai Thakker vs State Of Gujarat 1964 AIR 1563, 1964 SCR (7) 361
 (1878) 4 Couper 70.
 1964 AIR 1563