Missouri Revised Statutes Title XXXV. Civil Procedure and Limitations § 508.110. Judge disqualified, case transferred to another division of court, when

In all circuits composed of a single county which have more than four hundred thousand inhabitants, and in which there are two or more judges, when legal objection is made to the circuit judge assigned to try any case, the case shall be transferred to another division of the circuit court presided over by a different judge. Only one application shall be made by the same party in the same case, and shall be made as to only one of the judges of the court.