Mo. Rev. Stat. § 545.230

If a defendant be indicted by the wrong name, unless he declare his true name before pleading, he shall be proceeded against by the name in the indictment. If he allege that another name is his true name, it must be entered in the minutes of the court; and after such entry, the trial and all other proceedings on the indictment shall be had against him by that name, referring also to the name by which he is indicted, in the same manner, in all respects, and with the same consequences as if he had been indicted by his true name.