On 1st July 2024, the criminal justice system of India changed with the implementation of new laws: Bharatiya Nyaya Sanhita (BNS), Bharatiya Nagarik Suraksha Sanhita (BNSS) and Bharatiya Sakshya Adhiniyam (BSA). These legislations replaced Indian Penal Code, Code of Criminal Procedure and Indian Evidence Act, respectively.

Section 22 of Bharatiya Nyaya Sanhita (Formerly Section 84 IPC) is a part of Chapter III of General Exceptions. Section 22 BNS states that a person cannot be held criminally liable for an act if, at the time of committing it, they were suffering from a mental illness that made them incapable of understanding the nature of the act or knowing that it was wrong or unlawful. In other words, if someone commits an act while mentally ill and unable to understand their actions, the act does not amount to an offence under this provision. Explore other important Judiciary Notes.

Section 22 BNS: Act of a person of Unsound Mind

Nothing is an offence which is done by a person who, at the time of doing it, by reason of mental illness, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law.

Note: “The information provided on Section 22 BNS 2023 above has been sourced from the official website, i.e., Indian Code. While the content has been presented here for reference, no modifications have been made to the original laws and orders.”

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Section 22 of Bharatiya Nyaya Sanhita 2023 provides an exception to criminal liability for individuals who are mentally ill at the time of committing the act. An important aspect is the mental condition of the accused at the exact time the act was committed and not before or after. The emphasis is on the inability to comprehend:

• What the person is doing (nature of the act) or
• That the act is wrong or contrary to law.

Who is Considered a Person of Unsound Mind?

The Courts have elaborated the term “unsound mind” or “mental illness” under Section 22 BNS to include:

1. Idiots – Individuals with permanent cognitive disabilities from birth.
2. Persons ‘non compos mentis’ – Temporarily of unsound mind due to illness.
3. Lunatics or mad persons – Those suffering from periodic or chronic mental derangement.
4. Intoxicated persons – If the intoxication leads to a loss of mental faculties to the extent defined in the section.

Section 22 BNS 2023: Essential Ingredients

To successfully invoke the defense under Section 22 BNS there are certain essential conditions that must be met. These conditions, closely aligned with Section 84 of Indian Penal Code (IPC) which helps to determine whether the accused was liable at the time of the offence. The essential elements are as follows:

1. Unsoundness of Mind at the Time of the Act
   The person must be suffering from a mental illness at the moment of the offence.
2. Incapacity to Understand
   The person, due to mental illness, must be:

• Incapable of understanding the nature of the act, or
• Incapable of knowing the act is wrong or contrary to law.

1. Causation
   The incapacity must directly result from the mental illness.
2. Existence at the Time of the Offence
   The unsoundness must exist at the exact time the act is committed and not before or after.

Burden of Proof

As per Section 105 of the Indian Evidence Act, the burden to prove insanity or mental illness under Section 22 BNS lies on the accused. It must be established on a balance of probabilities and not beyond a reasonable doubt.

Origin of Insanity as a Defence

The concept of using insanity as a legal defence traces back to the landmark case of R v Arnold (1724), which introduced the “Wild Beast Test.” This test analysed whether an individual possessed the mental capability to comprehend the nature of their actions and differentiate between right and wrong.

Later, in R v Hadfield (1800), the “Insane Delusion Test” emerged with a similar objective. However, both tests were found to be inconsistent and inadequate in reliably determining the presence of insanity.

The turning point came with the case of R v McNaughton (1843), which established the “Right and Wrong Test” under what became known as the McNaughton’s Rule. In this case, Daniel McNaughton, suffering from a delusional disorder, mistakenly killed Edward Drummond, believing him to be Prime Minister Sir Robert Peel. His defence argued that he lacked the mental capacity to understand his actions, and he was acquitted on grounds of insanity.

This case laid the groundwork for the legal understanding of insanity and introduced core principles still used today, including:

• Presumption of sanity unless evidence proves otherwise
• Defect of reason due to a mental disorder at the time of the act
• Lack of awareness of the nature or wrongfulness of the act

What is McNaughton’s Rule?

The McNaughton Rule (also spelled M’Naghten Rule) is a legal standard for determining an accused person’s criminal liability based on their mental condition during the offence. Originating from R v McNaughton (1843), it provides that a person may be found not guilty by reason of insanity if, at the time of the offence:

• They were incapable of understanding the nature and consequences of the act due to a mental disorder, or
• They were unable to recognize that the act was morally or legally wrong.

Under this rule, the burden of proof lies on the defence to establish the existence of such mental incapacity at the time of the offence.

Applicability of the McNaughton Rule in India

In India, the concept of insanity as a defence is codified under Section 84 of the Indian Penal Code (Now Section 22 BNS). This section states that a person is not liable if, due to unsoundness of mind at the time of the act, they were unable to understand the nature of the act or that it was against the law.

This provision aligns with the broader legal principle: “Actus non facit reum nisi mens sit rea” which means that a person is not guilty unless there is both an act and a guilty mind.

Section 84 IPC (Now Section 22 BNS) reflects the core ideas of the McNaughton Rule, there are subtle differences. For instance, unlike McNaughton’s Rule, Section 84 does not explicitly use the term “quality of the act,” nor does it use the phrase “contrary to law.” Still, Indian courts have consistently interpreted Section 84 in line with McNaughton principles.

In Hazara Singh v. State, the principle of “furious nulla voluntas est” (a madman has no will) was discussed, indicating that not all mentally ill individuals qualify for this defence—only those who can prove legal insanity. This was further clarified in Bapu v. State of Rajasthan, where the court emphasized the distinction between legal and medical insanity.

The judiciary has reiterated in multiple rulings that mere strangeness, eccentric behaviour, or even mental illness does not automatically exempt one from criminal liability. It must be proven that the person suffered from cognitive incapacity that rendered them unable to understand the nature or wrongfulness of their actions.

In Dulal Naik v. State (1987), the court reaffirmed that McNaughton’s Rule must be read in conjunction with Section 105 of the Indian Evidence Act, which presumes sanity unless proven otherwise. The accused must demonstrate that the unsoundness of mind existed at the time of the offence—not merely before or after.

Legal Insanity vs Medical Insanity

The Courts consistently emphasize that only legal insanity, not mere medical insanity, qualifies for exemption under the law. The standard for legal insanity is clearly outlined in Section 84 of the Indian Penal Code (Now Section 22 BNS). Legal insanity refers to a mental condition where the person is incapable of understanding the nature of the act or that it was wrong or against the law at the time of committing the offence.

The IPC does not define “unsoundness of mind,” but the term is generally equated with the concept of insanity in legal interpretation. However, insanity has varying meanings in different contexts and levels of mental disorders. Merely being mentally ill, eccentric, or emotionally unstable does not automatically qualify a person for the legal defence of insanity. 

For instance, unusual behavior, mild intellectual weakness, epileptic episodes, or a history of fits or abnormal conduct while medically significant are not sufficient to invoke Section 84 (Now Section 22 BNS).

Medical professionals may diagnose such individuals as mentally ill, but from a legal standpoint, the accused must demonstrate that at the time of the act, their cognitive capacity was severely impaired—to the extent that they could not comprehend the act or recognize that it was unlawful or morally wrong.

The legal principle requires conclusive proof that the accused was suffering from a severe defect of reasoning due to a mental disorder at the moment of the offence. There must be clear evidence of delusion or mental instability affecting the person’s ability to understand their actions.

Difference between Legal Insanity and Medical Insanity

Legal insanity and medical insanity are distinct concepts that differ in their basis and implications. The following are the differences between the two:

Section 22 BNS: Case Law

The following are some of the Landmark Judgements that provide key insights into the application of the insanity defence under Section 22 BNS 2023 (Previously Section 84 of the IPC). The cases have shaped the judicial interpretation of the legal standards and criteria for determining whether an accused can be deemed legally insane at the time of the offence:

Ashiruddin Ahmed v. King (AIR 1949 Cal 182)

In this case, the Calcutta High Court explained the conditions under which an accused can invoke the defence of insanity under Section 84 of the IPC (Now Section 22 BNS). The court laid down that the accused must prove at least one of the following:

1. They did not understand the nature of the act committed; or
2. They were unaware that the act was contrary to the law; or
3. They did not comprehend that the act was morally wrong.

Dayabhai Chhagabhai Thakkar v. State of Gujarat (AIR 1964 SC 1563)

The Supreme Court in this judgment held that, to assess whether the accused falls under the scope of Section 84 IPC (Now Section 22 BNS), a holistic approach must be adopted. The Court highlighted that all circumstances surrounding the offence must be taken into account, including:

• Events before the offence
• The accused's mental history
• Their mental condition at the time of the act and
• Post-offence behavior that might reflect their cognitive state.

The case established that merely having a mental illness is not sufficient but the timing and influence of the illness on the act must be clearly proven.

Sudhakaran v. State of Kerala (AIR 2011 SC 265)

In this case, the Supreme Court examined a scenario where the accused murdered his wife but spared his child, taking steps to ensure the child’s care after the offence. The accused had a history of psychiatric treatment dating back to 1985 but provided no evidence of mental illness (Now Section 22 BNS) during or near the time of the offence. The Court held that:

• Prior treatment alone does not justify the plea of insanity,
• The burden lies on the accused to establish insanity at the time of the offence, and
• The accused failed to demonstrate any such condition during the incident.

Accordingly, the conviction and life sentence imposed by the High Court were upheld.

Surendra Mishra v. State of Jharkhand (AIR 2011 SC 627)

In this matter, the accused fatally shot the victim and claimed insanity as a defence. However, the Supreme Court found no proof that the accused was mentally unsound at the time of the offence (Section 22 BNS). It reiterated that:

• There must be cogent evidence of unsoundness of mind during the commission of the offence
• The legal burden to establish such a defence rests on the accused.

As the appellant could not substantiate his claim, the Court upheld the decision of the High Court and convicted him under Section 302 IPC and affirmed the life sentence.

Shine Kumar v. State of Kerala (2024)

In this case, the accused, Shine Kumar, was charged with murdering his parents while alone with them at home on 30th September 2015. Aged around 40 at the time, he was booked under Section 302 IPC. During trial, he denied the charges but the Sessions Court rejected his plea of legal insanity, noting the absence of motive and the fact that he did not attempt to flee after the incident. Dissatisfied with the verdict, he appealed to the Kerala High Court. The Division Bench comprising Justices PB Suresh Kumar and Johnson John took a broader view, observing that although lack of motive or flight alone does not prove insanity, in the unique circumstances of this case, those factors could not be ignored in assessing the accused’s mental state. The Court ultimately accepted the plea of insanity and extended the benefit of Section 84 IPC (Now Section 22 BNS), thereby setting aside the conviction.

Comparison: Section 22 BNS vs Section 84 IPC

The following table provides a difference between Section 22 BNS 2023 and Section 84 IPC. It highlights the key aspects such as terminology, modernization and legal principles involved in assessing mental fitness for criminal responsibility:

Conclusion

Section 22 BNS 2023 modernizes the defense of mental illness in criminal law by aligning with contemporary mental health standards, while Section 84 of the IPC remains grounded in older terminology and concepts. Both sections emphasize the lack of mental capacity to understand the nature or legality of the act, providing a legal safeguard for individuals who are mentally incapacitated at the time of committing an offence.