Mo. Rev. Stat. § 57.117: Deputy sheriff to be resident of state — or adjoining state — exception, Jackson County and City of St. Louis.

Hereafter no sheriff in this state shall appoint any under sheriff or deputy sheriff unless the person so appointed shall be, at the time of his or her appointment, a bona fide resident of this state or of an adjoining state. The provisions of this section authorizing the appointment of a person as an under sheriff or deputy sheriff who is a bona fide resident of an adjoining state shall not apply to a sheriff of any county with a charter form of government and with more than six hundred thousand but fewer than seven hundred thousand inhabitants or any city not within a county.