Mo. Rev. Stat. § 534.200
Current with changes from the 2023 Legislative Session
The complainant shall not be compelled to make further proof of the forcible entry or detainer than that he was lawfully possessed of the premises, and that the defendant unlawfully entered into and detained or unlawfully detained the same.
§ 534.200, RSMo
RSMo 1939 § 2844, A.L. 1945 p. 1089