Mo. Rev. Stat. § 544.310: Associate circuit judge may call associate.

It shall be lawful for any associate circuit judge to whom any complaint shall be made, or before whom any prisoner shall be brought, as herein provided, to associate with himself any other associate circuit judge of the same county, and the powers and duties herein mentioned may be executed by such two associate circuit judges so associated; and if there be a difference of opinion between the two associate circuit judges on any question, the decision of the former shall prevail.