Generally, Fed.R.Crim.P. 5, requires that an officer making an arrest under a warrant issued upon a complaint shall take the arrested person without unnecessary delay before the nearest available federal magistrate. In 1995, Rule 5 was amended to provide that "[a]n officer making an arrest under a warrant issued upon a complaint charging solely a violation of 18 U.S.C. § 1073 need not comply with this rule if the person arrested is transferred without unnecessary delay to the custody of appropriate state or local authorities in the district of arrest and an attorney for the government moves promptly, in the district in which the warrant was issued, to dismiss the complaint." The Advisory Committee note on the 1995 amendment to Rule 5 provides a useful discussion of post arrest procedures in UFAP cases.
Updated December 18, 2015