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 punished by imprisonment in the county jail for a period not to exceed one year, or by imprisonment in a state correctional facility for one, two, or three years.
(L. 1993 H.B. 562 § 2 subsec. 1, A.L. 2019 H.B. 397)