Section 1. Members of the provincial guards, city police and municipal police shall not be removed and, except in cases of resignation, shall not be discharged except for misconduct or incompetency, dishonesty, disloyalty to the Philippine Government, serious irregularities in the performance of their duties, and violation of law or duty, and in such cases, charges shall be preferred by the provincial governor in matters against any member of the provincial guards, the city mayor in cases against a member of the city police, and the municipal mayor in cases involving a member of the municipal police, and investigated by the provincial board, the city or municipal council, as the case may be, in public hearing, and the accused shall be given opportunity to make their defense. In every such case filed, a copy of the charges shall be furnished the accused by the said provincial governor, city mayor or municipal mayor personally or by registered mail, within five days from the date of the filing of the charges, and the investigating body shall try the case within ten days from the date the accused has been notified of the charge, unless the accused, for good reasons, shall ask for a longer period to prepare his defense. The trial of the case shall be finished within a reasonable time, and the investigating body shall decide the case within fifteen days from the time the case is submitted for decision.