That provision allows a federal court to grant a state prisoner the writ of habeas corpus "on the ground that he or she is in custody in. Federal prisoners in US Marshals custody may lawfully be transferred to the custody of a state or local government pursuant to a state writ of ad prosequendum.On February 4, 2022,2 Petitioner filed the Petition for Writ of Habeas Corpus in this case. Section 2241 constitutes the general habeas corpus statute under which federal prisoners may seek relief for claims of unlawful custody. If you are a federal prisoner, you will not file a state post-conviction proceeding. My family member is in the Allegheny County Jail (ACJ).