The incident occurred about 9 p.m. in the 1200 block of Mississippi Avenue SE, in the Congress Heights neighborhood.
Police said in a statement that the Pentagon officer flagged down a District officer, identified himself as law enforcement, reported the robbery and said he had fired his weapon. He said the youth ran. Moments later, police said, someone called 911 to report a shooting, and police found the injured youth a block away.
Police said the Pentagon officer told investigators that the youth pointed a gun at him and that the two “struggled over” the firearm. Police said the officer was unsuccessful in getting the weapon, and he then pulled his own gun and fired at least one shot.
Police said that investigators recovered a weapon believed to belong to the teenager and that it is a pellet gun. Police said they charged the youth as a juvenile with assault with intent to commit an armed robbery. The shooting is being investigated by D.C. police.
The Pentagon police, formally called the Pentagon Force Protection Agency, is a federal law enforcement agency that is part of the U.S. Department of Defense. Its members protect the occupants and visitors at the Pentagon in Virginia.
Chris Layman, the agency’s spokesman, said the officer who shot the teenager is a member of the department’s uniform division. He did not have immediate details on the officer’s status, nor did he identify the officer.
A new law requires D.C. police to publicly identify officers in its department within five days of a serious use-of-force incident, and unless the person shot or family objects, release video from the officer’s body-worn camera.
But that law does not cover officers from departments other than D.C. police.
Of the seven shootings of civilians by police in the District this year, two involved officers not assigned to the District — the shooting Wednesday and one on Feb. 25 by a security guard — known as a Special Police officer — who authorities said shot a suspected armed robbery suspect at a restaurant in Northeast Washington.
None of the shootings by police in the District this year has been fatal.