Mo. Rev. Stat. § 115.593
If the court or legislative body trying a contested election determines there were irregularities of sufficient magnitude to cast doubt on the validity of the initial election, it may order a new election for the contested office or on the contested question. The order shall set the date of the election and shall be sent by the clerk of the court or the secretary of the senate or the chief clerk of the house of representatives, as the case may be, to each election authority responsible for conducting the special election. In its order, the court or legislative body shall specify the name of each candidate for the office to be voted on at the special election, or the ballot title of the question to be voted on at the special election, and the election shall be conducted and the votes counted as in other elections. Notice of the election shall be given in such manner as the court or legislative body directs. The person receiving the highest number of votes at the special election shall be deemed elected and entitled to assume office, or the question submitted at the special election shall be deemed approved if a majority of the votes at the special election are cast in favor of the question.
§ 115.593, RSMo
Effective 1/1/1978