Mo. Rev. Stat. § 488.636

In addition to all other court costs for domestic relations cases, the circuit clerk shall collect an additional surcharge in the amount of two dollars per case for each domestic relations petition filed before a circuit judge or associate circuit judge. Such surcharges collected by circuit court clerks shall be collected and disbursed as provided by sections 488.010 to 488.020. Such fees shall be payable to the state treasurer, to be deposited into the Missouri CASA fund.