Mo. Rev. Stat. § 525.020: Garnishees summoned, how.

When a fieri facias shall be issued and placed in the hands of an officer for collection, it shall be the duty of the officer, when directed by the plaintiff, his agent or attorney, to summon garnishees, and with like effect as in case of an original attachment. The service of garnishment in such case, and the subsequent proceedings against and in behalf of the garnishee, shall be the same as in the case of garnishment under an attachment.