Mo. Rev. Stat. § 492.420

Depositions of witnesses to perpetuate testimony may be taken, whether the person desiring the taking of the same is a party, or expects to be a party, to a suit pending or about to be commenced or not, in any court of this state, and the object is to perpetuate the contents of any lost deed or other instrument of writing, or the remembrance of any fact, matter or thing necessary to the recovery, security or defense of any estate or property, real or personal, or any interest therein, or any other personal right.