Habeas Corpus, in the Federal Court, is a petition that claims that you are being detained against your US constitutional rights. A Writ of Habeas Corpus is a civil proceeding that is available in both State and Federal Court to challenge the legality of imprisonment.To get a writ of habeas corpus, you must file a petition for a civil (not criminal) proceeding in either state or federal court. The writ of habeas corpus primarily acts as a writ of inquiry, issued to test the reasons or grounds for restraint and detention. Translated from Latin it means "show me the body. The writ of habeas corpus, also known as the Great Writ, is a U.S. legal process that determines whether an offender's imprisonment is valid. It tests the legality of a detention or a restraint and the goal is to use it really almost i guess it's an emergency basis. Case file: the court file containing papers submitted in a case. American Civil Liberties Union Foundation v. Baxter, Judge ) denying his petition for a writ of habeas corpus under 28 U.S.C. § 2254.