D.C. Code § 22-4503.02: Prohibition of firearms from public or private property.

(a)

The District of Columbia may prohibit or restrict the possession of firearms on its property and any property under its control.

(b)

Private persons or entities owning property in the District of Columbia may prohibit or restrict the possession of firearms on their property; provided, that this subsection shall not apply to law enforcement personnel when lawfully authorized to enter onto private property.