Missouri constitution
Article V: judicial department
Section 25(a)

Whenever a vacancy shall occur in the office of
judge of any of the following courts of this state, to wit: The supreme court, the court
of appeals, or in the office of circuit or associate circuit judge within the city of St.
Louis and Jackson county, the governor shall fill such vacancy by appointing one of
three persons possessing the qualifications for such office, who shall be nominated and
whose names shall be submitted to the governor by a nonpartisan judicial commission
established and organized as hereinafter provided. If the governor fails to appoint any
of the nominees within sixty days after the list of nominees is submitted, the nonpartisan
judicial commission making the nomination shall appoint one of the nominees to
fill the vacancy.