US Capitol on Lockdown after Shooting

[Content Note: Guns; violence.]

NBC News reports that shots have been fired outside the US Capitol, and the building is subsequently on lockdown:

The United States Capitol was placed on lockdown Thursday afternoon after shots were fired in the vicinity of the chamber. At least one Capitol Police officer was injured, officials said.

The FBI was responding to the scene, and a helicopter landed in front of the Capitol. A message from the Capitol Police ordered anyone in a House office to "shelter in place."

"Close, lock and stay away from external doors and windows," the message said.

The House recessed, and the Senate went into a quorum call — dispensing momentarily with its official business — shortly thereafter.

"We've locked the doors. We closed the window shades. And we are awaiting further instructions," Rep. Jared Polis (D-Colo.) told MSNBC. "We're more or less cut off here. We're watching TV and just trying to figure out what happened."

CBS News is reporting that the lockdown has already been lifted, and that "a female gunman is reportedly dead on the scene," and Politico is reporting: "Two eyewitness said U.S. Capitol Police fired multiple shots at a black sedan on Constitution Avenue near the Hart Senate Office Building. Two people, including a child, were removed from the vehicle. One adult from the vehicle appeared to be hit by gunfire."

Information is very preliminary at the moment, so please note that these details are early reports and may change. I'll update as new/additional information becomes available, and please feel welcome and encouraged to share information in comments.

UPDATE: The Guardian's live update stream is here. I direct you there with a word of caution that they do post images from the scenes of shootings.

UPDATE 2: At this point, it's being reported that the "suspected shooter" did not fire a weapon at all and may have been unarmed, but instead was "taken down" by police after an attempted security breach at the White House.

UPDATE 3: Via the Guardian, here is a description of eyewitness video aired by CNN:

A black sedan is stopped outside the White House with multiple police vehicles parked around it including one directly behind it. A half-dozen officers stand around the vehicle, guns drawn. The vehicle reverses violently, hitting the police car behind it. Officers aim pistols at the driver's window and can be seen yelling. The car speeds away, forcing officers to jump to safety. Several pops – likely gunshots – are audible.

The car speeds from the White House and down Constitution Avenue toward the Capitol. Many police cars are in pursuit. The car leads police vehicles one full loop through a traffic circle, eluding them, and continues toward the Capitol.

The final wreck is not on the video.