45 CFR § 681.15 - How are the functions of the ALJ separated from those of the investigating official and the reviewing official?
(a) The investigating official, the reviewing official, and any employee or agent of the authority who takes part in investigating, preparing, or presenting a particular case may not, in such case or a factually related case:
(1) Participate in the hearing as the ALJ;
(3) Make the collection of penalties and assessment under 31 U.S.C. 3806.