A, a police officer, who has the right to arrest a person committing a cognizable offence, arrests B, mistakenly thinking that he has committed murder, when in fact he killed a dacoit in self-defence. In such a case:

IPC Wrongful Confinement (Section 340 IPC): Wrongful confinement refers to the intentional restraining of a person's liberty in a manner that violates the law. It involves detaining a person against their will in an enclosed space or within certain limits, without lawful authority. Wrongful Restraint (Section 339 IPC): Wrongful restraint involves preventing a person from proceeding in a direction in which that person has a right to proceed. It is the obstruction of a person's free movement or action without that person's consent or without legal justification. Illegal Detention: Illegal detention refers to the unlawful confinement or holding of a person against their will, often without following due legal process or justification. It can also refer to the illegal confinement of a person by the state authorities without lawful authority or justification