A writ of habeas corpus is another means to fighting the legality of one's incarceration or proving actual innocence. A writ of habeas corpus refers to a court order that is issued to either an agency or a person who is holding someone in custody.The writ of habeas corpus is the remedy to be used when any person is restrained in his liberty. In Texas, the state writ of habeas corpus is a legal mechanism that allows individuals to challenge their detention or imprisonment. An application for a writ of habeas corpus asks a court to overturn your conviction because of a state or federal constitutional violation. Federal habeas corpus is a procedure under which a federal court may review the legality of an individual's incarceration. What Is Habeas Corpus? Habeas corpus, which is Latin for "you may have the body," is a legal principle that protects against unlawful detention or imprisonment. The law in the area is an intricate weave of statute and case law. The Latin phrase habeas corpus translates to "you have the body.