Mo. Rev. Stat. § 390.171: Violation of law or rule a misdemeanor.

Every owner, officer, agent or employee of any motor carrier, and every other person, who violates or fails to comply with or who procures, aids or abets in the violation of any provision of this chapter, or who fails to obey, observe or comply with any order, decision, rule or regulation, direction, demand or requirement of the division, or who procures, aids or abets any person in his failure to obey, observe or comply with any such order, decision, rule, direction, demand or regulation thereof is guilty of a misdemeanor.