Mo. Rev. Stat. § 546.540: Confinement of insane persons, costs paid, how.

The sheriff or other officer having the custody of persons committed to the director of the department of mental health as provided in section 552.040 shall, if he deems it necessary to their safe custody, confine them to the county jail until they shall be removed to a state hospital. If all things needful be not otherwise supplied, he shall furnish them, and, in such cases, the supplies for the indigent shall be paid for by the proper county commissions out of the county treasuries; and supplies for others than the indigent shall be repaid out of their estates, and may be recovered by suit in the name of such officer.