It is the duty of each district attorney general, county attorney or city attorney to whom the commissioner reports any violation of this part, to cause appropriate proceedings to be instituted in the proper courts without delay and to be prosecuted in the manner required by law. Before any violation of this part is reported to any such attorney for the institution of a criminal proceeding, the person against whom such proceeding is contemplated shall be given appropriate notice and an opportunity to present such person's views before the commissioner, either orally or in writing, in person, or by attorney, with regard to such contemplated proceeding.