18 U.S.C. § 3623 — Transfer of a prisoner to State authority

The Director of the Bureau of Prisons must order that a prisoner who has been charged in an indictment or information with, or convicted of, a State felony, be transferred to an official detention facility within such State before his release from a Federal prison facility if—
(1) the transfer has been requested by the Governor or other executive authority of the State;
(2) the State has presented to the Director a certified copy of the indictment, information, or judgment of conviction; and
(3) the Director finds that the transfer would be in the public interest. If more than one request is presented about a prisoner, the Director must determine which request should receive preference. The expenses of such transfer must be borne by the State requesting the transfer.