Mo. Rev. Stat. § 575.080: False reports — penalty.

1. A person commits the offense of making a false report if he or she knowingly:

(1) Gives false information to any person for the purpose of implicating another person in an offense; or

(2) Makes a false report to a law enforcement officer that an offense has occurred or is about to occur; or

(3) Makes a false report or causes a false report to be made to a law enforcement officer, security officer, fire department or other organization, official or volunteer, which deals with emergencies involving danger to life or property that a fire or other incident calling for an emergency response has occurred or is about to occur.

2. It is a defense to a prosecution under subsection 1 of this section that the person retracted the false statement or report before the law enforcement officer or any other person took substantial action in reliance thereon.

3. The defendant shall have the burden of injecting the issue of retraction under subsection 2 of this section.

4. The offense of making a false report is a class B misdemeanor.