D.C. Mun. Regs. tit. 24, r. 24-1305
The Notice of Violation shall be served on the violator, the owner, the owner's authorized agent; the building superintendent, the operator of equipment, or other responsible individual at the premises by means of personal service, certified mail, or conspicuous posting.
If the respondent refuses to accept a Notice of Violation which is personally served, then the Department shall serve the notice by certified mail.
If the respondent refuses to accept a Notice of Violation which is served by certified mail, or is no longer at the last known address as shown on the tax records of the Department of Finance and Revenue and no forwarding address is available, then the Notice shall be considered to have been served on the date the return receipt bearing the notification is received by the Department of Public Works.
Upon request of the respondent, or his or her attorney or authorized agent, the Department shall provide a copy of the ticket issued to the respondent in a manner and at a cost established by the Director.
D.C. Mun. Regs. tit. 24, r. 24-1305