Section 185.115 - Separation of functions(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;(2) Participate or advise in the initial decision or the review of the initial decision by the authority head, except as a witness or a representative in public proceedings; or(3) Make the collection of penalties and assessments under section 3806 f title 31, United States Code.(b) The ALJ shall not be responsible to or subject to the supervision or direction of the investigating official or the reviewing official.