UPDATES: Capitol Gunman Identified, Was Known to Police
Update, 7:20 pm ET: Chief Washington correspondent James Rosen reported that law enforcement sources have unofficially identified the suspect as Larry Russell Dawson of Tennessee.
There are unconfirmed reports that Dawson was taken into custody last October, after an outburst on the House side of the Capitol.
Update, 4:53 pm ET: During a routine administrative screening at around 2:39 pm today, an adult male entered the U.S. Capitol Visitor Center, drew a weapon and pointed it at officers, said USCP Chief Matt Verderosa.
A police officer fired his gun and struck the suspect, who is now undergoing surgery in hospital, the chief said at a news conference.
It has not been determined how many officers fired their weapons. A weapon was recovered on the scene.
No officers were injured, Verderosa confirmed.
He said "an uninvolved 35 to 45-year old female bystander also suffered what appears to be minor injuries."
“I stress that much of this administration is still very preliminary,” said Verderosa.
He added that the suspect's car has been located and is being investigated.
“We believe that this is the act of a single person who has frequented the Capitol grounds before, and there is no reason to believe that this is anything more than a criminal act.”
Watch the press conference above.
Update, 4:44 pm ET: The shooter in custody was reportedly known to authorities, Charles Payne said on Your World.
Reports say the same person was arrested for an outburst in a House chamber just last year. He has also been accused of assaulting a police officer.
Former police detective Rod Wheeler tells Fox News that sources say authorities have not yet released the gunman's name as they are in the process of obtaining a search warrant.
Stay tuned to Fox News Channel for the upcoming police press conference.
Update, 3:55 pm ET: Fox News' Capitol Hill producer Chad Pergram reported that a male entered the North area on the Senate side of the Capitol's visitor center and pulled a gun.
Authorities now say that no U.S. Capitol police officers were wounded, but a bystander was wounded.
D.C. police say there is no longer an immediate threat to the public.
There has been an isolated incident at the US Capitol. There is no active threat to the public
— DC Police Department (@DCPoliceDept) March 28, 2016
Reports earlier had indicated a police officer had been shot.
"We do not know if there was an exchange of gunfire, but we do know that U.S. Capitol police officers fired and took down that individual. He was taken to the hospital," reported Pergram.
#BREAKING Sources tell me suspect's gun set off mags at Capitol Visitor's Center. 2 officers began shooting. Suspect & bystander wounded
— Chad Pergram (@ChadPergram) March 28, 2016
Update, 3:42 pm ET: Witnesses say that the shooting sounded like a full clip of a handgun had been emptied, though these accounts have not yet been confirmed.
The incident comes at the peak of the city's tourism season, with many middle school students in town on class trips and visitors flocking to see the cherry blossoms.
A U.S. Capitol police officer was shot and the shooter is in custody, AP just reported.
APNewsAlert: Capitol officials: 1 Capitol police officer shot, not seriously, shooter in custody.
— AP Politics (@AP_Politics) March 28, 2016
The officer was not seriously wounded. There is no longer a threat at the Capitol.
Capitol staffers were told to shelter in place and the White House was placed on lockdown after gunshots were reported at the Capitol visitor center.
Authorities have not released a description of the shooter.
Catherine Herridge said the incident occurred at a security screening checkpoint.
A security notice stated that one person was hit by "shrapnel" while the shooter was "down" and being taken to a hospital.
Witnesses reported a "number of shots" being fired.
There was an active shooter drill conducted this morning, Fox News' Chad Pergram reported this afternoon.
Congress is in recess so lawmakers are not at the Capitol today.
Stay tuned to Fox News Channel for updates on this developing story.