CLAT LLM 2010 Question Paper with answer key for online practice

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 act, seizes Z in order to bring Z before the proper authorities. It turns out later that Z was not committing murder but was acting in self defence. What offence has been committed by A? A is guilty of