After the filing of any such complaint, either by a person claiming to be aggrieved as set forth in § 4-1 or by the Commission, the Commission shall: investigate the facts alleged therein; and make a finding of probable cause for the said complaint or lack of it. City Code, 1966, art. 19, §56(b)(1st sen.) 1976/83, art. 19, §70(b)(1st sen.) Ord. 64-370 Ord. 66-739