You should use this form if. Federal habeas corpus is a procedure under which a federal court may review the legality of an individual's incarceration.Habeas corpus is a kind of petition that you can file in federal court to claim that your imprisonment violates federal law. Though subject to different rules, incarcerated people in both state or federal custody may petition for a federal writ of habeas corpus. What Is Habeas Corpus? Habeas corpus is a Latin phrase meaning "produce the body. An application for a writ of habeas corpus to release a prisoner confined under sentence of court must be brought in the county where the prisoner is confined. In this petition, you must explain why you believe you are being unlawfully detained and provide evidence to support your claim. To file a habeas corpus petition, you must prepare a written request to a court or judge, known as a writ of habeas corpus. ❖ Read this only if you need to file in a county in Washington State besides.