17 CFR § 10.9 - Separation of functions.
(a) An Administrative Law Judge will not be responsible to or subject to the supervision or direction of any officer, employee, or agent of the Commission engaged in the performance of investigative or prosecutorial functions for the Commission.
(b) No officer, employee or agent of the Commission who is engaged in the performance of investigative or prosecuting functions in connection with any proceeding shall, in that proceeding or any factually related proceeding, participate or advise in the decision of the Administrative Law Judge or the Commission except as witness or counsel in the proceeding, without the express written consent of the respondents in the proceeding. This provision shall not apply to the members of the Commission.