18 U.S.C. § 3184 : US Code - Section 3184: Fugitives from foreign country to United States

      Whenever there is a treaty or convention for extradition between
    the United States and any foreign government, or in cases arising
    under section 3181(b), any justice or judge of the United States,
    or any magistrate judge authorized so to do by a court of the
    United States, or any judge of a court of record of general
    jurisdiction of any State, may, upon complaint made under oath,
    charging any person found within his jurisdiction, with having
    committed within the jurisdiction of any such foreign government
    any of the crimes provided for by such treaty or convention, or
    provided for under section 3181(b), issue his warrant for the
    apprehension of the person so charged, that he may be brought
    before such justice, judge, or magistrate judge, to the end that
    the evidence of criminality may be heard and considered. Such
    complaint may be filed before and such warrant may be issued by a
    judge or magistrate judge of the United States District Court for
    the District of Columbia if the whereabouts within the United
    States of the person charged are not known or, if there is reason
    to believe the person will shortly enter the United States. If, on
    such hearing, he deems the evidence sufficient to sustain the
    charge under the provisions of the proper treaty or convention, or
    under section 3181(b), he shall certify the same, together with a
    copy of all the testimony taken before him, to the Secretary of
    State, that a warrant may issue upon the requisition of the proper
    authorities of such foreign government, for the surrender of such
    person, according to the stipulations of the treaty or convention;
    and he shall issue his warrant for the commitment of the person so
    charged to the proper jail, there to remain until such surrender
    shall be made.