Mo. Rev. Stat. § 115.033

Before entering upon his duties, each commissioner shall take and subscribe an oath to support the Constitution of the United States and of this state and to demean himself faithfully and impartially in office. Before entering upon his duties, each commissioner shall give bond to the state in the sum of ten thousand dollars, with security to be approved by the governor, conditioned for the faithful and honest performance of his duties and the care and preservation of the board's property. Not later than thirty days after a commissioner is sworn, his oath and bond shall be filed with the secretary of state.