Mo. Rev. Stat. § 575.260: Tampering with a judicial proceeding — penalty.

1. A person commits the offense of tampering with a judicial proceeding if, with the purpose to influence the official action of a judge, juror, special master, referee, arbitrator, state prosecuting or circuit attorney, state assistant prosecuting or circuit attorney, or attorney general in a judicial proceeding, he or she:

(1) Threatens or causes harm to any person or property; or

(2) Engages in conduct reasonably calculated to harass or alarm such official or juror; or

(3) Offers, confers, or agrees to confer any benefit, direct or indirect, upon such official or juror.

2. The offense of tampering with a judicial proceeding is a class D felony.