Mo. Rev. Stat. § 544.580

Sureties in recognizances or bail bonds in criminal cases and proceedings shall be residents of this state, and shall be worth, over and above the amount exempt from execution, and the amount of their debts and liabilities, the sum which is required; and the person or persons offered as sureties may be examined on oath in regard to their qualifications as sureties, and other proof may be taken in regard to the sufficiency of the same. The officer authorized to set conditions of release is authorized to administer all necessary oaths in that behalf.