Mo. Rev. Stat. § 327.201
Any person who practices professional engineering in Missouri as defined in section 327.181, who is not exempt pursuant to the provisions of section 327.191 and who is not the holder of a currently valid license or certificate of authority to practice professional engineering in Missouri, or who pretends or attempts to use as such person's own the license or certificate of authority or the seal of another professional engineer, or who affixes such person's or another professional engineer's seal on any plans, specifications, drawings or reports which have not been prepared by such person or under such person's immediate personal supervision is guilty of a class A misdemeanor.
(L. 1969 S.B. 117, A.L. 1981 S.B. 16, A.L. 1999 H.B. 343)