Mo. Rev. Stat. § 77.060: Councilman, qualifications.

No person shall be councilman unless he is at least twenty-one years of age prior to taking office, a citizen of the United States, and an inhabitant of the city for one year next preceding his election, and a resident of the ward from which he is elected six months next preceding his election. Whenever there is a tie in the election of a councilman, the matter shall be determined by the council.