Constitution of the State of Missouri
Article VII, Section 8
Section 8. Qualifications for public office-nonresidents.
No person shall be elected or appointed to any civil or military office in this state who is not a citizen of the United States, and who shall not have resided in this state one year next preceding his election or appointment, except that the residence in this state shall not be necessary in cases of appointment to administrative positions requiring technical or specialized skill or knowledge.