Mo. Rev. Stat. § 58.430: Witness attached may be discharged on bail.

When a writ of attachment, issued by the coroner, shall be executed, the officer may discharge such witness on his entering into recognizance to the state of Missouri, with sufficient bond, in the sum of one hundred dollars, with one or more sureties signing the same. The officer executing the writ is hereby authorized to take the same, providing for the appearance and due attendance of such witness, according to the command of such writ.