Mo. Rev. Stat. § 452.905: Role of prosecutor or public official.

1. In a case arising under sections 452.700 to 452.930 or involving the Hague Convention on the Civil Aspects of International Child Abduction, the appropriate public official may take any lawful action, including resort to a proceeding under sections 452.850 to 452.915 or any other available civil proceeding to locate a child, obtain the return of a child or enforce a child custody determination if there is:

(1) An existing child custody determination;

(2) A request from a court in a pending child custody case;

(3) A reasonable belief that a criminal statute has been violated; or

(4) A reasonable belief that the child has been wrongfully removed or retained in violation of the Hague Convention on the Civil Aspects of International Child Abduction.

2. A prosecutor or an appropriate public official shall act on behalf of the court and shall not represent any party to a child custody determination.