Mo. Rev. Stat. § 517.132
Current with changes from the 2023 Legislative Session
If any suit, setoff, counterclaim or cross claim is based upon a written instrument purporting to have been executed by the opposite party, and the same or a verified copy is filed with the court, such instrument shall be admitted in evidence at trial unless the opposing party by responsive pleadings or affidavit shall deny the execution of the instrument, prior to admission of the instrument in evidence.
§ 517.132, RSMo