If any person, being required by a conservator of the peace on view of a breach of the peace or other offense to bring before him the offender, refuse or neglect to obey the conservator of the peace, he shall be guilty of a Class 2 misdemeanor; and if the conservator of the peace declare himself or be known to be such to the person so refusing or neglecting, ignorance of his office shall not be pleaded as an excuse.
Va. Code § 18.2-464