Within ten (10) working days of the completion of an evidentiary hearing, and within thirty-five (35) working days of the receipt of complaint, the Commission shall issue a written report containing findings of fact and a determination of whether the complaint is sustained to the Attorney General’s Office and to the Chief of Police along with its recommendation for disposition. If the Commission, after the evidentiary hearing, determines that further investigation is necessary and directs further investigation, it shall include such finding in its report and shall not be required to disclose any further findings until the additional investigation is complete and an evidentiary hearing thereon is held consistent with the provisions of this Act.