District of Columbia Code Division I. Government of District. § 7-2502.02. Registration of certain firearms prohibited.

(A) Any organization that employs at least one commissioned special police officer or other employee licensed to carry a firearm and that arms the employee with a firearm during the employee's duty hours;

(B) A police officer who has retired from the Metropolitan Police Department;

(C) Any person who seeks to register a pistol:

(D) A firearms instructor, or an organization that employs a firearms instructor, for the purpose of conducting firearms training.

(A) The applicant meets the requirements of § 7-2502.03; and

(B) A unique serial number is engraved or cast on, or otherwise permanently affixed to, the firearm in a manner that meets or exceeds the requirements imposed on licensed importers and licensed manufacturers of firearms pursuant to 18 U.S.C. § 923(i) and regulations issued pursuant thereto; provided, that a serial number or mark of identification exceeds these requirements if the engraving, casting, or stamping (also known as impressing) of the serial number exceeds the required minimum depth or exceeds the minimum print size of that provision.

(2)(A) An applicant who meets the requirements of § 7-2502.03 may register a self-manufactured firearm that does not bear a serial number as described in paragraph (1)(B) of this subsection, if, prior to finishing the frame or receiver, the applicant has caused a unique serial number to be engraved, casted, stamped (impressed), or placed on the frame or receiver, as set forth in subparagraphs (B) and (C) of this paragraph.

(B) The serial number shall consist of the first and last name of the self-manufacturer, followed by the designation “DC” and then a set of 2 to 5 numbers.

(C) The set of numbers described in subparagraph (B) of this paragraph shall not duplicate any serial number placed by the self-manufacturer on any other firearm. The applicant shall, before engraving, casting, stamping (impressing), or placing a serial number on the frame or receiver, confirm with the Metropolitan Police Department that the proposed serial number has not already been registered to another firearm.