Legal insanity defence requires proof of incapacity at the time of the offence; mere mental illness is insufficient.

Section 84 of the Indian Penal Code applies only where the accused proves legal insanity at the time of the offence and shows incapacity to know the nature of the act or that it was wrong or contrary to law. The burden lies on the accused under Section 105 of the Indian Evidence Act and must be discharged on a preponderance of probabilities. On the facts discussed, repeated assaults, conduct suggesting awareness, lack of reliable medical material for continuous unsoundness, and surrounding circumstances did not establish the plea. The conviction under Sections 302 and 307 was therefore upheld.

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Issues: Whether the appellant was entitled to the benefit of Section 84 of the Indian Penal Code, 1860 on the plea of unsoundness of mind at the time of the incident, and whether the conviction under Sections 302 and 307 of the Indian Penal Code, 1860 was liable to be interfered with.

Analysis: The plea under Section 84 required proof of legal insanity at the time of the occurrence, not merely medical insanity or occasional mental illness. The burden to bring the case within the general exception lay on the accused under Section 105 of the Indian Evidence Act, 1872, on a preponderance of probabilities. The evidence showed repeated assaults, conduct consistent with understanding the act, absence of reliable medical material showing continuous unsoundness at the relevant time, and no satisfactory proof that the appellant was incapable of knowing the nature of the act or that it was wrong or contrary to law. The subsequent arrest and the surrounding circumstances also did not support the plea of insanity.

Conclusion: The appellant was not entitled to the benefit of Section 84 of the Indian Penal Code, 1860. The conviction under Sections 302 and 307 of the Indian Penal Code, 1860 was upheld.

Final Conclusion: The criminal appeal failed and the judgment of conviction and sentence was affirmed.

Ratio Decidendi: To claim exemption under Section 84 of the Indian Penal Code, 1860, the accused must prove legal insanity at the time of the offence so as to show incapacity to know the nature of the act or its wrongfulness, and mere proof of mental weakness or intermittent psychosis is insufficient.

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