Habeas corpus

In common law countries, habeas corpus (/ˈheɪbiəs ˈkɔɹpəs/) (Latinwrit, through which a person can seek relief from unlawful detention of themselves or another person. The writ of habeas corpus has historically been an important instrument for the safeguarding of individual freedom against arbitrary state action.

Also known as "The Great Writ," a writ of habeas corpus ad subjiciendum is a court order addressed to a prison official (or other custodian) ordering that a prisoner be brought before the court so that the court can determine whether that person is serving a lawful sentence or should be released from custody. The prisoner, or some other person on his behalf (for example, where the prisoner is being held incommunicado), may petition the court or an individual judge for a writ of habeas corpus.

The right of habeas corpus—or rather, the right to petition for the writ—has long been celebrated as the most efficient safeguard of the liberty of the subject. Dicey wrote that the Habeas Corpus Acts "declare no principle and define no rights, but they are for practical purposes worth a hundred constitutional articles guaranteeing individual liberty." In most countries, however, the procedure of habeas corpus can be suspended in time of national emergency. In most civil law jurisdictions, comparable provisions exist, but they may not be called "habeas corpus."

The writ of habeas corpus is one of what are called the "extraordinary", "common law", or "prerogative writs", which were historically issued by the courts in the name of the monarch to control inferior courts and public authorities within the kingdom. The most common of the other such prerogative writs are quo warranto, prohibito, mandamus, procedendo, and certiorari.

The due process for such petitions is not simply civil or criminal, because they incorporate the presumption of nonauthority, so that the official who is the respondent has the burden to prove his authority to do or not do something, failing which the court has no discretion but to decide for the petitioner, who may be any person, not just an interested party. In this they differ from a motion in a civil process in which the burden of proof is on the movant, and in which there can be an issue of standing.