Mo. Rev. Stat. § 575.300: Misconduct by a juror — penalty.

1. A juror commits the offense of misconduct by a juror if he or she knowingly:

(1) Promises or agrees, prior to the submission of a cause to the jury for deliberation, to vote for or agree to a verdict for or against any party in a judicial proceeding; or

(2) Receives any paper, evidence or information from anyone in relation to any judicial proceeding for the trial of which he has been or may be sworn, without the authority of the court or officer before whom such proceeding is pending, and does not immediately disclose the same to such court or officer.

2. The offense of misconduct by a juror is a class A misdemeanor.