D.C. Code § 51-105

Any nonresident employer, for whom services constituting employment subject to this subchapter are performed, shall be deemed to have appointed the Director of the Department of Transportation of the District of Columbia as his true and lawful attorney upon whom may be served all processes in any action or proceedings against such nonresident arising out of, or incident to, this subchapter, and said employment shall be a signification that any such process against him served, as herein provided, shall have the same effect and validity as if served on him personally in the District of Columbia. Service of such process shall be made by leaving a copy thereof (with a fee of $2) in the hands of the Director of the Department of Transportation of the District of Columbia, or other persons in charge of his office, and such service shall be sufficient service upon such nonresident; provided, that notice of such service and a copy of the process are forthwith sent, by registered mail, by the plaintiff to the defendant and the defendant’s return receipt attached to the writ and entered with the initial pleading. The court in which the action is pending may order such extensions as may be necessary to afford the defendant a reasonable opportunity to defend the action, and no judgment by default in any such action shall be granted until at least 20 days shall have elapsed after the notice of such service has been sent to the defendant as hereinabove prescribed.