Mo. Rev. Stat. § 545.370: Witness to attend until end of case — consequences of failure to so attend.

Whenever a witness in a criminal case has been once subpoenaed or recognized to appear before any division of the circuit court, he shall attend under the same as such witness, from time to time, and from term to term, until the case be disposed of, or he be finally discharged by the court; and he shall be liable to attachment for any default or failure to appear as such witness, and adjudged to pay the costs and such fine as the court may properly impose; and no costs shall be allowed for any subsequent recognizance or subpoena for any such witness.