Mo. Rev. Stat. § 115.557: Election contest to be filed, when.

Not later than thirty days after the official announcement of the election result by the secretary of state, any person authorized by section 115.553 who wishes to contest the election for any office or on any question provided in section 115.555, shall file a verified petition in the office of the clerk of the supreme court. The petition shall set forth the points on which the contestant wishes to contest the election and the facts he will prove in support of such points, and shall pray leave to produce his proof. The supreme court shall have exclusive jurisdiction over all matters relating to the contest and may issue appropriate orders to all election authorities in the area in which the contested election was held.