Mo. Rev. Stat. § 56.085: Criminal investigations, prosecutors or circuit attorneys may obtain subpoena for witnesses, records and books.

In the course of a criminal investigation, the prosecuting or circuit attorney may request the circuit or associate circuit judge to issue a subpoena to any witness who may have information for the purpose of oral examination under oath to require the production of books, papers, records, or other material of any evidentiary nature at the office of the prosecuting or circuit attorney requesting the subpoena.