Missouri Revised Statutes Title XXXV. Civil Procedure and Limitations § 511.200. Judgment set aside--contents of petition

No such judgment shall be set aside unless the petition for review shall state the existence of the facts set forth in section 511.170, and that the petition of plaintiff, upon which the judgment complained of was obtained, is untrue in some material matter, setting it forth, or that he has and then had a good defense thereto, setting such defense forth, or both, and then only on condition that the defendant answer or direct a motion to the petition of plaintiff on which the judgment was rendered within a reasonable time, to be ordered by the court. Such petition for review shall be verified by affidavit of the defendant or his attorney of record.