Mo. Rev. Stat. § 491.330: Associate circuit judge may order witness attached, when.

Whenever it shall appear to the satisfaction of the associate circuit judge that any person duly subpoenaed to appear before him in a suit shall have failed without just cause to attend as a witness in conformity to such subpoena, and the party in whose behalf the subpoena was issued, or his attorney, shall make oath that the testimony of such witness is material, the associate circuit judge shall have power to issue an attachment to compel the attendance of such witness.