The official text
Old and new, side by side
Indian Penal Code, 1860
Section 79 Act done by a person justified, or by mistake of fact believing himself, justified, by law
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.
A sees Z commit what appears to A to 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.
Bharatiya Nyaya Sanhita, 2023
Section 17 Act done by a person justified, or by mistake of fact believing himself justified, by law
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.
Illustration.
A sees Z commit what appears to A to 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.
The texts are India Code’s. The amendment markers and footnotes of the official print are left out, so the old section reads as it stood when it was repealed; State amendments are not shown. The PDFs linked below carry the full history.