Mo. Rev. Stat. § 441.090
Current with changes from the 2023 Legislative Session
Every tenant on whom a summons in an action to recover the tenements held by him shall be served shall forthwith give notice thereof to the person, or the agent of the person, of whom such tenant holds, under the penalty of forfeiting to such person the value of three years' rent of the premises occupied by him.
§ 441.090, RSMo
RSMo 1939 § 2963