When the offense charged is a misdemeanor, the magistrate or court, before issuing the warrant, may require the complainant, or if the magistrate considers the complainant irresponsible, may require that said complainant procure a person to be liable for the costs if the complaint is dismissed, and the complainant or other person shall acknowledge himself so liable, and such court or magistrate shall enter such acknowledgment on his docket. Such bond shall not be required of an officer authorized to make arrests when in the discharge of his official duty, or other person or officer authorized to assist the prosecuting attorney in the prosecution of offenders.