Mancusi v. DeForte, 392 U.S. 364 (1968), is a decision of the United States Supreme Court on privacy and the Fourth Amendment. It originated in the lower courts as United States ex rel. Frank DeForte, appellant v. Vincent R. Mancusi, Warden of Attica Prison, Attica, New York, appellee, a petition for a writ of habeas corpus by a prisoner who had exhausted all his state appeals. By a 6–3 margin the Court affirmed the United States Court of Appeals for the Second Circuit's reversal of a district court denial of the petition.