Mo. Rev. Stat. § 578.423
Any person who actively participates in any criminal street gang with knowledge that its members engage in or have engaged in a pattern of criminal street gang activity, and who willfully promotes, furthers, or assists in any felonious criminal conduct by gang members shall be guilty of a class B felony.
(L. 1993 H.B. 562 § 2 subsec. 1, A.L. 2019 H.B. 397, A.L. 2020 S.B. 600)