Mo. Rev. Stat. § 545.480: Additional affidavit, when made.

If the defendant will, in addition to the oath requisite in ordinary and timely applications, swear that the facts on which he grounds his application have first come to his knowledge since the last preceding continuance of the cause, the court may grant a change of venue, although such application be made at a term subsequent to that at which the prisoner was likely to be arraigned.