Mo. Rev. Stat. § 388.640
388.640 License as peace officer required.
388.640. License as peace officer required. — All railroad policemen who become employed after September 28, 1971, shall, before appointment, be a licensed peace officer in accordance with the provisions of chapter 590 .
(L. 1971 H.B. 232 § 9, A.L. 2002 S.B. 1213)