Mo. Rev. Stat. § 447.624: Proceeding, where commenced, procedure.

The proceedings shall be commenced by filing a verified petition in the circuit court in the county in which the property is located. The petition shall allege that the property meets the conditions to be declared abandoned pursuant to the provisions of section 447.622. All parties in interest of the property shall be named as defendants in the petition and summons shall be issued and service had as in other civil cases.