By The Washington Post · Clarence Williams, Anne Gearan, Carol D. Leonnig, Martin Weil · NATIONAL, COURTSLAW, WHITEHOUSE
The agency said the man and a Secret Service officer were taken to the hospital after the incident. The D.C. Fire Department was dispatched to the area at 5:55 p.m. Monday after receiving a call from the Secret Service reporting that an officer had shot a person in the upper body, D.C. fire spokesman Doug Buchanan said.
Trump spoke about the shooting after he returned to the briefing room. He said he knew nothing about the person's condition but added that he understood the person was armed.
Two law enforcement officials with knowledge of the investigation said no weapon was recovered at the scene.
U.S. Secret Service spokeswoman Julia McMurray declined to answer questions about the shooting, including what circumstances preceded the incident.
"This is an ongoing investigation, and we cannot comment further at this time," McMurray said.
On Twitter, the Secret Service said no entry was made into the White House complex, and none of those under the service's protection were ever in danger.
The FBI referred questions to the Secret Service.
D.C. Police Chief Peter Newsham said his department was involved in investigating the incident.
The shooting may have occurred at a Secret Service checkpoint for vehicles located about one block from the northwest gate to the White House grounds.
Vehicles are not permitted past the checkpoint.
In May 2016, a man was shot by the Secret Service a few blocks south. The man approached a guard booth and refused repeated orders to drop a pistol, authorities said.
It was not immediately clear what prompted Monday's shooting.
A video posted on Twitter by an apparent passerby showed law enforcement gathered, an officer wearing rubber gloves on his knees amid what appear to be bags of medical gear.
Just before Trump's briefing at the White House was interrupted, law enforcement could be seen taking positions on the driveway in front of the entrance to the press room. A uniformed officer appeared outside the double doors and locked them from the outside.
Then the president's Secret Service agent approached him and spoke quietly before they exited the room.
Trump later said he was escorted to the Oval Office.
Reporters said they received no additional information. The doors stayed locked.
The Secret Service also shut down the row of television stalls outside, where correspondents report with the White House in the background.
The president later returned to the lectern without fanfare or announcement. Trump was asked whether he had been rattled by the incident.
"I don't know," he replied, "do I seem rattled?"
"It's unfortunate," he said, adding that the world has "always been a dangerous place."
After the briefing, the doors remained locked for more than 20 minutes. When reporters and others in the room were released, they were directed to exit using a rear service entrance.