D.C. Code § 49-509

Whenever it shall appear to a regularly constituted court-martial convened under the provisions of this chapter that the accused, having been duly ordered or summoned to appear before such court-martial for trial, has refused or neglected so to appear, such court-martial shall issue a warrant or attachment for the arrest of the accused, directed to the United States Marshal for the District of Columbia, who shall forthwith execute said warrant or attachment, make proper return thereof to such court-martial, and produce to such court-martial the body of the accused, if within the District of Columbia, and to retain the custody thereof and continue so to produce said body during the sessions of such court-martial until the conclusion of the trial, unless sooner discharged by said court-martial.