This story has been updated.
When members of the group saw the officers, they ran, and officers pursued. During the chase, one member of the group drew a gun, and officers fired, according to the police account.
The person who drew the gun was hit and was pronounced dead at the scene, the statement said. Police Chief Peter Newsham, who went to the scene, said the person was male and appeared to be an adult.
The man was not named Tuesday night, pending notification of relatives.
Newsham said a gun was found at the scene. “We recovered the weapon from the suspect,” he said. In a photograph, the weapon appeared to be a semiautomatic pistol.
The site of the shooting is on the western edge of the Washington Highlands area and about 200 yards east of South Capitol Street.
No officers involved were hit by gunfire, police said, and none of them was named as of late Tuesday.
Newsham tied the incident to the presence of illegal guns in the city.
“We’ve got to get these illegal firearms out of our community,” the chief said.
He said he saw no reason why anybody needs to be standing “in any alley in D.C. armed with an illegal firearm.”
The fatal shooting was the second involving police in the Washington area in two days.
Police in Montgomery County, Md., shot and killed a man Monday in a confrontation in the Silver Spring area.