Introduction
Criminal insanity refers to a mental illness or disease that makes it impossible for the defendant to know that he is committing a crime or to understand that his actions are wrong. A defendant who is found to be criminally insane may raise the defence of insanity.

The first use of the insanity defence in the United States took place in Cayuga County, New York in People v. William Freeman (1847).

Tests to Determine Insanity
In different places, courts use various tests to determine if someone is legally insane. These tests include:
The "McNaughten Rule": This test looks at whether the person didn't understand what he was doing or couldn't tell right from wrong due to a mental illness.

The "Irresistible Impulse" Test: Here, it's about whether a mental illness made the person unable to control his impulses, which then led to a criminal act.

The "Durham Rule": This test considers whether the person's mental problem, no matter how it's clinically diagnosed, caused him to commit a crime.

The "Model Penal Code" Test for Legal Insanity: This one examines whether the person, because of a diagnosed mental issue, either didn't realize his actions were wrong or couldn't follow the law's rules.

Types of Insanity
Temporary Insanity: Occurs periodically or for a specific period, often linked to conditions like depression, anxiety disorders, schizophrenia, eating disorders, or addictive behaviours. Legal outcomes can include 'not guilty because insane' or 'guilty but cannot be tried because insane.'

Permanent Insanity: A continuous mental illness where past records and events demonstrate a lasting incapacity to comprehend the seriousness of situations.

Indian Scenario
In India, Section 84 of the IPC deals with "act of a person of unsound mind". "Nothing is a crime which is committed by him who, at the time he does it, by reason of unsound mind, is incapable of knowing the nature of the act, or not knowing what he was doing was either wrong or contrary to law."

Section 105 of the Indian Evidence Act 1872: Section 105 of the Indian Evidence Act says that when someone is accused of having done something and he claims that he did not do it, it is his duty to prove that he did not do it. In other words, if you are accused of something and you claim to be innocent, you must provide proof or evidence to support your claim of innocence. This section places the burden of proof on a person who denies having done the alleged act.

In order to avail benefit of Section 84 IPC, the accused has to prove legal insanity and not medical insanity. Any person suffering from any mental infirmity is called medical insanity, but legal insanity means that a person suffering from mental illness should also have loss of reasoning power. Additionally, legal insanity must be present at the time of the incident.

The text in Section 84 of the implementing regulation clarifies that two conditions must be met. First, the person must have been sane at the time he committed the crime, which is often called "medical insanity." Second, because of his mental unsoundness, he must be incapable of understanding the nature of the act or that it is wrong or unlawful, which is called "legal insanity."

There are three options for this second condition:

• He does not understand the nature of the act (cognitive incapacity).
• Even if he understands the act, he does not know that it is wrong (moral incapacity).
• Even if he understands the act, he does not know that it is against the law.

These three options explain the legal standard that must be proved in order for the accused to successfully assert the defence of insanity.

Court Judgments
In the legal matter of State of Madhya Pradesh v. Ahamadullah AIR 1961 SC 998, it was held that the burden of proof is on the accused to show that he was suffering from mental disorder at the time he committed the act.

The Supreme Court in Surendra Mishra v. State of Jharkhand (2011) 11 SCC 495 held that an accused seeking acquittal under Section 84 of the Indian Penal Code has to prove legal insanity and not medical insanity.

In the case of Shrikant Anandrao Bhosale v. State of Maharashtra, the Supreme Court held that when a person claims that he was legally insane when he committed a crime, it is important to consider his state of mind at the time the crime occurred. To determine whether he should get benefit from Section 84 of the Indian Penal Code, which deals with legal insanity as a defence, you have to look at the circumstances leading up to the crime, during and after the offence. In other words, in order to invoke this exception in one's favour, it is necessary to prove that the accused was actually legally insane at the time he committed the crime.

Innocent By Reason of Mental Incapacity
"Not guilty by reason of insanity" is a shaky defence that covers a variety of mental states. The law believes that a criminal cannot be held responsible for his actions if that person does not perceive reality.

Other definitions include whether the person can tell right from wrong, whether he can control his behaviour, and whether he intends to act as he did.

Forensic psychiatrists and psychologists know that explaining the mind of a criminal in these terms is not easy. Many with mental problems know right from wrong, understand reality, are not subject to irresistible urges, and can predict the results of their actions.

When ordinary neighbours commit insane crimes, they often live in their own reality. A loving mother suffocates her children to save them from an evil world, or a reliable co-worker turns out to be a schizoid serial killer.

Case Study
David Berkowitz, also known as 'Son of Sam', was a serial killer in New York City in the 1970s. He wrote a strange letter to the police claiming to be the 'Son of Sam' and referring to 'Papa Sam' keeping him locked in the attic. He was caught in 1977 because he got a parking ticket near the scene of his last murder, and a search of his car revealed the murder weapon.

Berkowitz tried to explain his actions by believing that the howling dogs in his neighbourhood were possessed by ancient demons, and those demons ordered him to kill. This could be considered an insanity plea, but he eventually pleaded guilty to killing six people and was sentenced to six life terms in 1978.

On the other hand, Andrea Yates drowned her five children one by one in a bathtub in 2001 in Houston, Texas. She was found not guilty by reason of insanity at her second trial in 2006. Her defence argued that she suffered from severe postpartum psychosis and was in a delusional state where she believed Satan was inside her and thought she was saving her children from hell. She was initially found guilty, but that verdict was overturned and she was sent to a mental institution instead.

Conclusion
If a disturbed or mentally ill person commits a crime but lives in our reality, the courts will often find them criminally responsible. In the US it can land them on death row. Several prisoners described as "mentally retarded" have been executed, but the US Supreme Court ruled in 2002 that the execution of mentally retarded prisoners violates constitutional protections against "cruel and unusual punishment". Psychiatrists have pointed to other differences in the minds of violent offenders.

Some have a marked lack of empathy for their victims, some are unable to control their behaviour, and others have predisposing factors such as a history of an abusive father. If a disturbed or mentally ill person commits a crime but believes in our reality, the courts will often find them criminally responsible.

References:

1. Criminal Investigation, Evidence, Clues and Forensic Science, John D. Wright, Parragon
2. https://www.law.cornell.edu/wex/criminal_insanity
3. https://www.taxmanagementindia.com/visitor/detail_article.asp?ArticleID=10600
4. https://main.sci.gov.in/supremecourt/2009/12564/12564_2009_8_104_40920_Judgement_1 2-Jan-2023.pdf
5. http://nujslawreview.org/wp-content/uploads/2021/08/14.2-AK-Misra-Surendranath.pdf
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676201/

Written By: Md. Imran Wahab, IPS, IGP, Provisioning, West Bengal
Email: [email protected], Ph no: 9836576565