A state is not required by the federal constitution to provide a right to appellate review at all, but where a state does not provide a right to appeal and imprisons a person, a writ of habeas corpus is practically always available in a higher court to give relief against an unjust incarceration. Now the theory and practice of writs gets complicated in a hurry. Suffice it to say that the great majority of judicial proceedings in America today are under streamlined, simplified procedures that were introduced in the early twentieth century to replace a congery of nonstandard writ practices. In a few areas, the old forms still raise their generally ugly heads. One of these is habeas corpus writ procedure. If one person holds another, and the prisoner claims to be held contrary to law, the prisoner may apply to a court for a writ of habeas corpus ("Habeas corpus" means "you have the body of another person[, a prisoner]."). If the court finds that the writ application makes out a proper prima facie case that the prisoner is being held illegally, the court will issue the writ, which summons the person who holds the prisoner and the prisoner to court to determine whether the prisoner is in fact being held contrary to law, and issuing whatever orders are necessary to conform the imprisonment to law up to and including, in a proper case, an order to release the prisoner.
Habeas corpus offers relief for people being held for trial illegally before the trial. It offers relief for convicts who no longer have a right to appeal or in addition to appellate rights they have. It offers relief for people who are held in contempt of court, for which there is generally no right to appeal, and it offers a practical solution for plain old false imprisonment under color of law or not under color of law.
This post talks about the basic theory of habeas corpus. Next week we'll talk about rules that determine when, and in which courts, habeas corpus relief can be sought.