Missouri constitution
Article V: judicial department
Section 23

Each circuit
may have such municipal judges as provided by law and the necessary non-judicial
personnel assisting them. The selection, tenure and compensation of such judges and
such personnel shall be as provided by law, or in cities having a charter form of government
as provided by such charter. A municipal judge may be a part-time judge except
where prohibited by ordinance or charter of the municipality. A municipal judge shall
hear and determine violations of municipal ordinances in one or more municipalities.
Until otherwise provided by law, or supreme court rule, the practice, procedure, right to
and method of appeal before and from municipal judges shall be as heretofore provided
with respect to municipal courts. Associate circuit judges shall hear and determine
violations of municipal ordinances in any municipality with a population of under four
hundred thousand within the circuit for which a municipal judge is not provided, or
upon request of the governing body of any municipality with a population of under four
hundred thousand within the circuit.