Reports are coming in over the wire that gunshots were reported moments ago at the U.S. Capitol Visitors Center. Workers were told to "shelter in place" over the PA systems.
Congress and the White House went into lockdown immediately following the reports. Nearby roads were also shut down.
A Capitol police officer was shot, but not seriously injured.
The suspect is now in custody, according to Capitol officials.
Check back as this story is developing.
UPDATE 5:30 PM EST: Previous reports indicated that a Capitol police officer was injured in the shooting but that report was incorrect. No officers were injured. One female bystander suffered minor injured during the incident, new reports say. She was not shot, but may have been injured in the chaos or was hit by shrapnel.
The shooter has been identified as Larry Dawson, 66, of Tennessee. Daily Mail states: "The suspect has been identified by ABC News as Donald Trump supporter Larry Dawson, of Tennessee, who was arrested in the US Capitol for interrupting a House session in October to shout 'I am a prophet of God'."
Dawson was then charged with assaulting a police officer and unlawful conduct on Capitol grounds.
Dawson is said to have just entered the visitor's center and produced a gun after setting off the metal detectors at the security check. That's when an officer fired a shot that injured the suspect. He was rushed to surgery.
Oddly enough, this incident happened after a scheduled active shooter drill occurred, leaving staff confused for a brief moment.