Rule 78.05.After-Trial Motions, Including a Motion for a New Trial Based Upon Affidavits.

Rule 78.05 handles a practical problem: some after-trial motions rest on facts that never made it into the trial record, such as evidence of jury misconduct that no one could raise during the trial itself. This rule provides the mechanism for putting that outside-the-record evidence before the court.

When an after-trial motion, including a motion for new trial, relies on facts not appearing of record, the moving party may file affidavits, and those affidavits must be served along with the motion. The opposing party then has ten days after service to serve its own opposing affidavits. That ten-day window is not rigid — it may be extended for an additional period of up to twenty days, either by the court for good cause or by written stipulation between the parties.

The rule does not stop at affidavits. The court may permit reply affidavits, and it may also allow depositions and oral testimony to be presented in connection with the after-trial motion. That range of options gives the court flexibility to develop a factual record adequate to decide a motion that could not have been resolved on the trial record alone.

The official comment describes this rule as substantially carrying forward a prior rule's approach, so the affidavit procedure it sets out reflects an established part of Missouri's after-trial practice instead of a new mechanism.