The Metropolitan Police Department said officers responded around 10:41 p.m. to the shooting in the 4700 block of 1st Street, near the border of D.C. and Prince George's County.
Once there, officers found a man inside a residential building who had been shot.
The victim, who has not been identified, was transported to the Office of the Chief Medical Examiner and later pronounced dead.
Investigators have not indicated a possible motive or released a lookout in connection with the shooting.
Anyone with information is asked to MPD at 202-727-9099 or send a text message tip to 50411.
A reward of up to $25,000 is being offered for information that leads to an arrest and conviction in the case.