Mo. Rev. Stat. § 287.780: Discrimination because of exercising compensation rights prohibited — civil action for damages — motivating factor defined.

No employer or agent shall discharge or discriminate against any employee for exercising any of his or her rights under this chapter when the exercising of such rights is the motivating factor in the discharge or discrimination. Any employee who has been discharged or discriminated against in such manner shall have a civil action for damages against his or her employer. For purposes of this section, "motivating factor" shall mean that the employee's exercise of his or her rights under this chapter actually played a role in the discharge or discrimination and had a determinative influence on the discharge or discrimination.