Section 17 BNS: Act Done by Person Justified, or by Mistake of Fact Believing Justified by Law (Formerly Section 79 IPC)

Section 17 of Bharatiya Nyaya Sanhita: Act Done by Person Justified, or by Mistake of Fact Believing Justified by Law

Official Bare Act Text

Override / Mandate Mens Rea (Intent) Actus Reus (Conduct) Punishment Limitation Monetary

Nothing is an offence which is done by any person who is justified by law, or who by reason of a mistake of fact and not by reason of a mistake of law in good faith, believes himself to be justified by law, in doing it.

Illustrations

Asees Z commit what appears toAto be a murder.A, in the exercise, to the best of his judgment exerted in good faith, of the power which the law gives to all persons of apprehending murderers in the fact, seizes Z, in order to bring Z before the proper authorities. A has committed no offence, though it may turn out that Z was acting in self-defence.

Legal Commentary & Landmark Judgments: Section 17

Section 17 establishes that nothing is an offence which is done by any person who is justified by law, or who by reason of a mistake of fact and not by reason of a mistake of law in good faith believes himself to be justified by law.

Justified by Law: Applies where the law affirmatively authorizes or empowers a citizen or officer to act (e.g. private arrest under Section 40 BNSS).
Mistake of Fact Defense: Protects a person who honestly and reasonably misapprehends physical facts (e.g. mistaking a friend acting in a drama for a real robber).
Due Care and Attention: The mistake must be made in good faith after exercising reasonable inquiry and caution under the circumstances.

Key Landmark Precedents:

Chirangi v. State (1952) Cri LJ 1212: The Nagpur High Court acquitted a father who, in a state of delusion in a forest, mistook his son for a tiger and killed him, holding that the act was protected as a bona fide mistake of fact under Section 79 IPC (Section 17 BNS).
Keso Sahu v. Saligram Shah (1977) Cri LJ 1725: Held that a citizen who arrests a person mistakenly believing in good faith that a cognizable offence was committed is protected under this section.

Courtroom Practice & Strategic Litigation Guidance:

In assault or wrongful confinement trials where a citizen intervened to prevent what appeared to be an armed robbery or child abduction, lead evidence of lighting, screaming, and surrounding circumstances to establish bona fide mistake of fact under Section 17 BNS.

Section 17: Act Done by Person Justified, or by Mistake of Fact Believing Justified by Law

Section 17 of Bharatiya Nyaya Sanhita: Act Done by Person Justified, or by Mistake of Fact Believing Justified by Law

Legal Commentary & Landmark Judgments: Section 17