Mo. Rev. Stat. § 532.100: Custodian of prisoner, how designated.

On such writ the person having the custody of the prisoner may be designated either by his name of office, if he have any, or by his own name; or, if both names be uncertain or unknown, he may be described by an assumed appellation; and the person directed to be produced may be designated by his name, or if his name be uncertain or unknown, he may be described in any other way, so as to designate the person intended.