Insanity Defense in Criminal Proceedings
By Chinnamma KC
According to section 84 of the Indian Penal Code (1860), any person who at the time of the commission of a crime was incapable of knowing the nature or illegality of such act shall not be held liable for such an act. Section 84 of IPC is based on McNaughten rules, named after McNaughten, an English man who murdered another man while suffering under the delusion that he was being persecuted by the Tories.According to the maxim Actus reus non facit reum nisi mens sit rea, an act does not make a defendant guilty without a guilty mind. Section 84 is, in its essence, a derivative of this maxim. To constitute a crime, both a mental element (mens rea) as well as a physical element (actus reus) must be present. Furiosi nulla voluntas est i.e. a person with mental illness has no free will. The rule of mens rea requires that a person committing an act must do so of his own free will, intentionally and for rational reasons. When a person suffers from unsoundness of mind and loses rational thinking and the sense of judgement, he fails to comprehend the nature and consequence of his actions. Hence, a person of unsound mind cannot be held responsible for any crime committed by him.
According to a forensic psychiatric study conducted on 5024 prisoners in India, 27.6% of the prisoners were found to be suffering from some type of diagnosable mental disorder. An important issue which arises while discussing section 84 is whether every person who suffers from a mental illness can be held to be of unsound mind as required by this section. It also raises the question whether every person who suffers from a mental illness is incapable of making rational decisions and understanding the nature and consequences of his actions. The concept of medical insanity and legal insanity are different. The Supreme Court in its judgment in Surendra Mishra versus State of Jharkhand clarified this point. The court rejected the insanity plea of the accused on the grounds that an accused cannot be acquitted solely on the fact that he was suffering from a certain mental illness, it was also required to prove that such mental illness rendered the accused unable to ascertain the nature and consequences of his act. The court while ascertaining if the mental illness of the accused rendered him legally insane can take into consideration the subsequent conduct of the accused. It could be any attempt to hide the evidence of the crime, to escape from the police, etc. as such actions indicate that the accused is aware of the consequences of his act. From the above, it can be safely concluded that legal insanity only arises when a man loses his ability to think, judge and act rationally and not merely because he suffers from a mental illness.
Normally, the law presumes that every person is legally sane and is aware of the law. When an accused takes a plea of insanity, the burden of proof is on the defence. Instances of accused persons pleading insanity falsely to escape the consequences of their criminal acts is not unheard of. Such instances have occurred and will also occur in the future. Hence, the courts require that for a person to be held legally insane, the defence has to prove the same beyond reasonable doubt. The defence can make use of expert evidence, oral and documentary evidence to prove legal insanity. Mere abnormality of mind or partial delusion, irresistible impulse or compulsive behaviour of a psychopath does not merit protection under Section 84 of IPC. If such a defense is taken during investigation, the investigating officer must ensure that the accused is subjected to a medical examination to determine his mental state. The accused may be subjected to such a medical examination even if he doesn’t plead insanity in cases where the Magistrate himself feels that the accused suffers from unsoundness of mind.The defense of insanity can only be taken at the investigation stage and the trial stage and not when the case reaches the appellate stage.
Though the law provides for all these measures to determine the mental condition of the accused, it is up to the court to decide whether the accused meets the criteria of legal insanity. In each case, the court takes into consideration the facts and circumstances to determine whether the accused is of unsound mind. This provision ensures that mentally ill persons are not unduly prosecuted and are provided the necessary medical treatment that they require. Many countries like USA, UK and France have similar laws related to insanity as a defence for criminal prosecution.
However, the fact that there is ample scope for this provision to be misused cannot be disputed. Ultimately, the responsibility of making sure that this provision is not misused rests with the judiciary.
 Daniel Mc Naughten's Case. 1843, 8 Eng. Rep. 718.
 Asokan TV. Daniel McNaughton (1813-1865) Indian J Psychiatry. 2007.
 MAYANK VATS & LEEPAKSHI RAJPAL, LEGAL DIMENSIONS WITH REFERENCE TO INSANITY UNDER SECTION 84 OF THE INDIAN PENAL CODE, IMPACT Journal, Vol.5, Issue 3,(March 2017).
 Math SB, Murthy P, Parthasarathy R, Naveen Kumar C, Madhusudhan S. Mental Health and Substance Use Problems in Prisons. The Bangalore Prison Mental Health Study: Local Lessons for National Action. Publication, National Institute of Mental Health and Neuro Sciences, Bangalore. 2011.
 (2011) 11 SCC 495.
 Jai Lal v. Delhi Administration, AIR 1969 SC 15.
 K.M.Sharma, DEFENCE OF INSANITY IN INDIAN CRIMINAL LAW, Journal of the Indian Law Institute, Vol. 7, No. 4 (OCTOBER-DECEMBER 1965).
 State of Rajasthan v. Shera Ram, (2012) 1 SCC 602.
 Gajraj Singh vs State of Rajasthan, Criminal Appeal No. 1313/2006 (Supreme Court, 2007).
 Section 328 of Code of Criminal Procedure, 1973.
 Section 329 of Code of Criminal Procedure, 1973.
 Supra at note 3.
 Akshay Sreevatsa, A short history of the insanity defence, MyLaw Blog, (Aug. 4, 2012), available at http://blog.mylaw.net/a-short-history-of-the-insanity-defence/.