D.C. Code § 5-742
In determining eligibility for the amount of benefits from the Policemen and Firemen's Relief Fund, District of Columbia, or the District of Columbia Police Officers and Fire Fighters' Retirement Fund (established by § 1-712 ), each member of the Metropolitan Police Department of the District of Columbia, the United States Park Police force, the United States Secret Service Uniformed Division, the Fire Department of the District of Columbia, and each member of the United States Secret Service who has actively performed duties other than clerical for 10 years or more directly related to the protection of the President, who shall have left active employment in any such Department, force, or Service to perform active service in the military or naval forces of the United States, shall be credited with all periods of honorable active military or naval service performed on or after September 16, 1940, and prior to the termination of the war as declared by Presidential proclamation or concurrent resolution of the Congress.
D.C. Code § 5-742
Coverage Under Federal Employees' Retirement Act: Officers and members of the United States Park Police, United States Secret Service Uniformed Division, and United States Secret Service Division hired on or after January 1, 1984, are covered by the Federal Employees' Retirement System Act, not the District of Columbia Retirement System, unless exempt from coverage of such Act. See 5 U.S.C. §§ 8401(17)(B) and 8402.