(a) Whenever this part becomes applicable, the attorney for the government shall promptly file with the sentencing court a proposed Judgment and Order. The proposed Judgment and Order shall state, in addition to any other matters required by law or otherwise appropriate, that:
(1) The sentence shall be executed by a United States Marshal designated by the Director of the United States Marshals Service;
(2) The sentence shall be executed by intravenous injection of a lethal substance or substances in a quantity sufficient to cause death;
(3) The sentence shall be executed on a date and at a place designated by the Director of the Federal Bureau of Prisons; and
(4) The prisoner under sentence of death shall be committed to the custody of the Attorney General or his authorized representative for appropriate detention pending execution of the sentence.
(b) The attorney for the government shall append to the proposed Judgment and Order a Return by which the designated United States Marshal may inform the court that the sentence of death has been executed.