Mo. Rev. Stat. § 540.310
Current with changes from the 2023 Legislative Session
No member of a grand jury shall be obliged or allowed to testify or declare in what manner he or any other member of the grand jury voted on any question before them, or what opinions were expressed by any juror in relation to any such question.
§ 540.310, RSMo
RSMo 1939 § 3923