Mo. Rev. Stat. § 84.120
No person shall be appointed or employed as policeman, turnkey, or officer of police who shall have been convicted of, or against whom any indictment may be pending, for any offense, the punishment of which may be confinement in the penitentiary; nor shall any person be so appointed who is not of good character, or who is not a citizen of the United States, or who is not able to read and write the English language, or who does not possess ordinary physical strength and courage. The patrolmen and turnkeys hereafter appointed shall serve while they shall faithfully perform their duties and possess mental and physical ability and be subject to removal only for cause after a hearing by the boards, who are hereby invested with the exclusive jurisdiction in the premises.
(RSMo 1939 § 7692, A.L. 1943 p. 703, A.L. 1945 p. 1257, A. 1949 H.B. 2033)
Prior revisions: 1929 § 7544; 1919 § 8954; 1909 § 9806