The Rhode Island Petition for Relief From a Conviction or Sentence By a Person in State Custody — (28 U.S.C. 2254) is a writ of habeas corpus that allows a person in state custody to seek relief from a conviction or sentence. This writ is available to any person who is “in custody in violation of the Constitution or laws or treaties of the United States” and who is “in custody in violation of the laws of a State.” This writ provides a person in state custody with the ability to challenge their conviction or sentence by asserting one of a variety of constitutional grounds. There are two types of Rhode Island Petition for Relief From a Conviction or Sentence By a Person in State Custody — (28 U.S.C. 2254). The first type is a petition for writ of habeas corpus ad prosequendum, which allows a person in custody to be brought to federal court to challenge their conviction or sentence. The second type is a petition for writ of habeas corpus ad subjiciendum, which allows a person in custody to challenge their conviction or sentence while remaining in state custody. In both cases, the court must determine if the writ is appropriate to grant the person in custody relief from their conviction or sentence.