Law recognizes the concept actus non facit reum nisi mens sit rea, and amens ne sine mente i.e. the physical act alone does not make a person guilty; the mental component in the form of evil intent (guilty mind) is equally important. This gives rise to the general exceptions that are given under the Indian Penal Code.

The Indian Penal Code, 1860 recognizes defenses in chapter four under the heading General Exceptions. Sections 76 to 106 of the IPC cover these defenses. The law offers certain defenses that exculpate criminal liability. These defenses are based on the premise that though the person committed the offense, he cannot be held liable. This is because, at the time of the commission of the offense, either the prevailing circumstances were such that the act of the person was justified or his condition was such that he could not form the requisite men's rea for the crime.

An excusable act is the one in which though the person has caused harm, it is held that a person should be excused because he cannot be blamed for the act. For example if a person of unsound mind commits a crime, he cannot be held responsible for being mentally sick.

Insanity Laws:
The defense of insanity is used by the defense to save their clients from capital punishment. It is based on the assumption that at the time of the crime, the defendant was suffering from severe mental illness and therefore, was incapable of appreciating the nature of the crime and differentiating right from wrong behavior, hence making them not legally accountable for the crime. The insanity defense is a legal concept, not a clinical one (medical one). This means that just suffering from a mental disorder is not sufficient to prove insanity. The defendant has the burden of proving the defense of insanity by a preponderance of the evidence which is similar to a civil case. It is hard to determine legal insanity, and even harder to successfully defend it in court.

Section 84 deals with the defense of insanity and is defined under the act as:
Nothing is an offense which is done by a person who, at the time of doing it, because 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.

History:
The insanity defense has been in existence for many centuries; however, it took a legal position only since the last three centuries. Section 8 of the IPC is based on Mc Nauqhten's rules of 1843 in England. Mr. Daniel Mc Naughten, while laboring under the delusion of persecution killed Mr. Edmund Drummond, the private secretary of British Prime Minister Mr. Robert Peel in mistake for the latter.

It was shown that Mc Naughten had transacted a business shortly before the act and had shown no signs of insanity. The defense put forth the plea of insanity and the accused was acquitted. Due to adverse public reaction, the House of Lords decided to probe into the subject.

Accordingly, some questions were put 180 before a bench of 14 judges in House of Lords. From the answers are given some rules were framed towards determination of criminal responsibility of insane and were called Mc Naughten rules. It states that:
to establish a defense on the grounds of insanity, it must be clearly proved that at the time of committing the act (or making the omission), the accused was laboring under such a defect of reason from disease of the mind as not to know the nature and quality of the act he was doing, or if he knew what he was doing, that he did not know it was wrong.

Mc�Naughten�s Rule
There have been several tests from time to time, like the Wild Beast Test, Insane Delusion Test, etc. But the most important is the Right and Wrong Test formulated in M'Naughten's case.

The hearing of M'Naughten and his release was a topic of discussion in House of Lords, and as a consequence, they called upon fifteen judges to decide on the question of criminal liability in the cases where the accused is incapable of understanding the nature of the act and also answered the questions advanced. Fourteen judges had the same answers. The view of the majority was given by Tindal C.J., these answers to the questions are known as M'Naughten's Rule. The following principles were cited:

1. If the person knew what he was doing or was only under a partial delusion, then he is punishable
2. There is an assumption that every man is prudent or sane and knows what he is doing and is responsible for the same.
3. To establish a defense based on insanity, it must be ascertained, at the time of perpetrating the act, the accused was in such a state of mind as was unable to know the nature of the act committed by him.
4. A person who has sufficient medical knowledge, or is a medical man and is familiar with the disease of insanity cannot be asked to give his opinion because it is for the jury to determine, and decide upon the questions.

Essential ingredients:
After evaluating and analyzing the insanity sections, the essential ingredients can be divided into three parts. It is necessary for the application of Section 84 to show

• That the accused was of unsound mind;
• That he was of unsound mind at the time he did the act and not merely before or after the act; and
• That as a result of unsoundness of mind, he was incapable of knowing the nature of the act and that what he was doing was either wrong or contrary to law.

Further is the explanation and relevant case laws for each of these sections for a better understanding as to how the courts decide and evaluate all of these ingredients.

Unsoundness of mind:
Unsoundness of mind is used to describe only those conditions that affect the cognitive capacity of an individual. So, every person who is mentally ill is not relieved from his responsibilities. Here the law makes a distinction between medical and legal insanity. There is a great difference between legal insanity and medical insanity, merely the doctors examination cannot be used to gain benefit but it is to be proved that the accused as a result of unsoundness of mind he was incapable of knowing the nature of the act and that what he was doing was either wrong or contrary to law.

This distinction is further elaborated in the case of:
The State Of Maharashtra vs Sindhi Alias Raman, S/O Dalwai on 4 August 1987, it was noted that,
There is a clear distinction between legal insanity and medical insanity. Medical insanity may be of various types, kinds, and degrees. To what extent medical insanity affects the cognitive faculties of a person will naturally depend upon the nature of that insanity.

A person may be suffering from some form of insanity recognized by the doctors as such, but that form of insanity may not necessarily be the unsoundness of mind contemplated by Section 84 of the I.P.C. If despite the insanity, which the doctor may find in a particular person, that person can recognize the nature and the quality of the act for which he is tried or if he is capable of knowing that what he was doing was either wrong or was contrary to law, then the benefit of Section 84 of the I.P.C. naturally would not be available to him.

In the case of Surendra Mishra v. the State of Jharkhand,
it was pointed out that every person who is suffering from the mental disease is not ipso facto exempted from criminal liability.

Unsoundness should exist at the time of the act:
Another requirement under law is that this unsoundness of mind should exist at the time of the commission of the act. It is only if the person is suffering from insanity when the act matters and not before or after that. If insanity exists at the time of trial it can only lead to postponement of trial but not to the acquittal of the accused.

Although insanity before and after the act can be a factor to be considered for reasoning if the person was truly insane at the time of the commission of the act. Shrikant Anandrao Bhosale v. the State of Maharashtra, the Supreme Court while determining an offense under Section 84 of IPC opined that it is the totality of the circumstances seen in the light of the evidence on record which would prove that the Appellant, in that case, was suffering from the said condition. It was added: The unsoundness of mind before and after the incident is a relevant fact.

An accused young boy was brought up by his grandfather and studied abroad. His parents did not care about him; even his grandfather's death was not communicated to him. On coming to India he committed brutal offenses at random. During the pendency of the trial, he completed his studies and started his own business. His behavior was normal before and after the offense. But -was held insane while committing the offense and was acquitted.

In the case of Sarjerao Rambhau Machale Vs. The State of Maharashtra held that:
the accused was not liable for punishment as they were insane at the time of the commission of the crime. Therefore the accused was acquitted.

Nature of the act:
If the accused did not know the nature of the act he was committing then he is not responsible for it., Similarly, if he knew the nature of the act but did not know whether it was wrong or contrary to the law he is not liable. On the other hand, if the person did not know the nature of the act but knew that it is wrong as contrary to the law he is held responsible.

In the case of X v. State of NCT of Delhi, it was held that at the time of committing the offense the accused was suffering from mental diseases and was a chronic mental patient and did not know the nature of the act committed. Hence in this recent decision, the high court acquitted the accused due to this.

Roles of the Courts and Examiners:
A standard evaluation procedure of all patients who plead the insanity defense is necessary. It is Unfortunately that to date, no such standardized procedures exist in our country. Psychiatrists are often called for conducting mental health evaluations and treatment. Apart from treatment, courts may also request various certifications.

This includes:
Certifying the presence or absence of psychiatric illness if the defendant claims for an insanity plea
Assessment of fitness to stand trial in cases where mental illness incapacitates cognitive, emotional, and behavioral faculties of an individual causing serious impact on the ability to defend the case.
While courts themselves apply some tests for determining if a person is criminally insane. These tests can vary for different jurisdictions. These include:
The M'Naghten Rule
The Irresistible Impulse Test
The Durham Rule

Role Of Psychiatrists:
Psychiatrists are often called for conducting mental health evaluations and treatment. Apart from treatment, courts may also request various certifications. This includes:

1. Certifying the presence or absence of psychiatric illness if the defendant claims for an insanity plea (defendant's mental status when the alleged offense took place);
2. Assessment of fitness to stand trial in cases where mental illness incapacitates cognitive, emotional, and behavioral faculties of an individual causing serious impact on the ability to defend the case (defendant's present mental status and his competence during adjudication).

Psychiatrist should consider inpatient admission for a comprehensive evaluation of the defendant.

It is the duty of the psychiatrist to educate the court, clarify psychiatrically issues, provide honest and objective opinions based on factual data and sound reasoning. Forensic psychiatry assessment proforma, a modified version of the Kumar et al. 2014.

This NIMHANS Detailed Workup Proforma for Forensic Psychiatry Patients-II is used in the Institute for many decades for semi-structured assessment of forensic psychiatric cases. This proforma is modified periodically as per the clinical evaluation and legal requirements.

Review of accompanying documents
It is the duty of the psychiatrist to review all the accompanying legal documents and ascertain the referring authority, the reason for referral, date and time of referral, and available time in hand to provide the opinion. Further defendant's medical and psychiatric records should be reviewed before initiating the assessment of the defendant. A careful history should be gathered from all possible sources such as the defendant, accompanying person, FIR, postmortem and autopsy report, photographs of the crime scene, behavior observational report, interviewing the family members, and past treating psychiatrist.

Assessment of history of presenting illness
The accused should be interviewed as early as possible in time to the offense though practically, this may not always be feasible. At the outset of the assessment, the defendant must be informed about the purpose of the evaluation and the lack of confidentiality. The psychiatrist should document the date and time of assessment, demographic details, identification marks, and injuries on the body. A comprehensive inquiry should be done into the history of presenting illness, history, family history, personal history, and premorbid personality. The psychiatrist should never forget to assess substance use in the past and present.

Assessment focusing on mental state at the time of the offense
The psychiatrist should make an effort to evaluate the defendant's mental status at the time of the offense. He should try to get a detailed account of the incident through open-ended questions. It would be prudent to ask the defendant to give a step-by-step account of his behavior, emotions, biological, occupational, and social functioning beginning 1-week before the offense and to be enquired till 1-week after the commission of the offense.

The comprehensive inquiry should be done on his cognition, behavior, emotions, and perception, prior, during, and immediately after the commission of the offense. The psychiatrist should enquire by asking open-ended questions to ascertain the defendant's knowledge of the law, the nature of his act, and also whether he is in a position to appreciate right and wrong.

Mental Status and cognitive functioning assessment
The mental status examination should be done without leading questions. The psychiatrist should ask open-ended questions and he should restraint himself from asking leading questions. An in-experienced psychiatrist can fall easily into the trap of malingering patients. Hence, it is advisable to admit the patient and do a serial mental status examination and serial ward observations.

Diagnosis
Considering the nature of the assessment and law presumes everyone is sane unless the contrary is proved, it is prudent to start assessment in the same direction. The psychiatrist should resist making a definitive diagnosis initially. Diagnosis needs to be kept the open or provisional diagnosis to be considered. After gathering information from all possible sources, depending upon the serial mental status examination, serial ward observation, psychological testing and laboratory investigations, the psychiatrist should make an honest objective assessment and give his opinion regarding the patient's lifetime diagnosis and present mental status. He should also make a sincere effort to opine on the mental status of the defendant during the commission of the offense

Conclusion:
It can be said that the laws relating to this field are well established already in India. The insanity plea in India is scrutinized to the utmost importance so that no false pleas can pass through and no dangerous person can be set free. The successful scrutinizing is evident from the data of pleas being successful for insanity. Insanity pleas had a success rate of about 17% in Indian High Courts in the past decade.

Thus it can be said that the plea of insanity serves its purpose with a well-established legal system and hence protects the interests of the society at the same time. It is suggested that there should be a well-defined definition of the term mental insanity to avoid the various controversies and confusions that arise in understanding and differentiating between the mental disease and the actual insanity of mind sought by the Code or the so-called legal insanity to make the defense available to the accused.

Section 84 of The code should be amended to incorporate the partial defense of diminished responsibility for murdering insane persons. This change shall be made on an equal footing with the defense of diminished responsibility as accepted under the defense of insanity as specified by English criminal law. The scope of Section 84 should be expanded to incorporate the defense of automatism under the defense of an unhealthy mind, just as it is recognized by the English criminal law system.