No idea what’s happened, but the Capitol is being locked down. Per NRO’s Robert Costa, members of Congress were outside at the time but no word yet on whether anyone’s hurt. Stand by for updates.

Update: They may already have the shooter:

No word on injuries yet, if any. For what it’s worth, GOP Rep. Sean Duffy had a weird altercation outside the Capitol last night with a strange man, who screamed at him and grabbed his arm. I’m mentioning that not because there’s any evidence linking that with the shooting, but because it’s an odd coincidence that there’d be violence of any sort outside the Capitol twice in a span of 12 hours.

Update: MSNBC says a U.S. Capitol police officer has been shot. I’m seeing rumors on Twitter that it’s related to a car chase but no confirmation.

Update: More on the car chase:

Update: “Capitol police tell National Journal that there are injured USCP officers, but the numbers are unconfirmed.”

Update: Hmmmmm.

Update: Reports now of one dead — the person behind the wheel of the car:

Update: At just before 3 p.m. ET, the lockdown in the Capitol has been lifted.

Update: The driver had a baby in the car with her. The baby’s reportedly unharmed.

Update: Surprise — early reports may have been wrong.

Update: Some good news: The Capitol police officer who was injured wasn’t shot.

Update: Jake Tapper’s show is reporting that all of the shots came from police.

Update: Madness via Ace.