Mo. Rev. Stat. § 66.030

All informations involving violation of county ordinances shall be made by the county counselor, or his assistants, on their oath of office and shall be filed with the court as soon as practicable, and before the party accused shall be put upon his trial or required to answer the charge for which he may be held in custody; provided, that complaints subscribed and sworn to by any other person competent to testify against the accused shall be filed and proceeded upon in the same manner as complaints alleging the commission of a misdemeanor.