Mo. Rev. Stat. § 441.820

The court may issue orders to protect persons that may be called as witnesses in a civil action brought pursuant to sections 441.710 to 441.880. An order may issue upon a showing that the witness has been threatened, intimidated or otherwise has reason to fear for their safety if they are called as a witness in the cause of action. Protective orders issued pursuant to sections 441.710 to 441.880 may include, but are not limited to, the nondisclosure of names, addresses or the in camera examination of witnesses.