Mo. Rev. Stat. § 191.908: Whistleblower protections — violations, penalty.

1. An employer shall not discharge, demote, suspend, threaten, harass, or otherwise discriminate against an employee in the terms and conditions of employment because the employee initiates, assists in, or participates in a proceeding or court action under sections 191.900 to 191.910. Such prohibition shall not apply to an employment action against an employee who:

(1) The court finds brought a frivolous or clearly vexatious claim;

(2) The court finds to have planned, initiated, or participated in the conduct upon which the action is brought; or

(3) Is convicted of criminal conduct arising from a violation of sections 191.900 to 191.910.

2. An employer who violates this section is liable to the employee for all of the following:

(1) Reinstatement to the employee's position without loss of seniority;

(2) Two times the amount of lost back pay;

(3) Interest on the back pay at the rate of one percent over the prime rate.