Law enforcement officials say terrorism is not suspected in a deadly confrontation outside the U.S. Capitol that began when a man rammed his auto into two officers outside the Capitol and then emerged wielding a knife.
Acting Capitol Police Chief Yogananda Pittman later identified the fallen officer as William F. Evans, an 18-year veteran of the force who was part of the First Responder's Unit.
He said the area was "swarming with police officers".
The complex was locked down in the aftermath of the January 6 riot, and a National Guard contingent of around 2,300 troops was still stationed in the area as of Friday.
A law enforcement official says officers were responding to a report of a possible shooting on a street near the Capitol complex. It comes as the Washington region remains on edge almost three months after a mob of armed insurrectionists stormed the Capitol as Congress was voting to certify Joe Biden's presidential win.
A heavy emergency services presence around the scene in the Capitol.
There was no immediate connection apparent between January 6 and Friday afternoon's crash. The suspect was not known to police, and the attack does not appear to be related to terrorism, she said.
The incident occurred as both the House and Senate were in recess, though both buildings have staff - and reporters - working inside. The incident came as lawmakers and authorities were still recovering from a deadly riot inside the Capitol building almost three months ago that saw five deaths.
But CBS News reported that security officials had already warned congressional staffers of a threat before the vehicle ramming.
The incident comes almost three months after the deadly 6 January riot at the Capitol. He exited the vehicle and began "lunging" toward police with a knife visible in his hand, at which point officers fired their weapons, killing the suspect.
When the incident occurred, police alerted staff members: "Due to an external security threat located All U.S. Capitol Campus Buildings, no entry or exit is permitted at this time", the alert reads.
Neither the U.S. Senate nor the House of Representatives was in session Friday, as Congress is in recess.
Video posted online showed a dark-coloured sedan crashed against a vehicle barrier and a police K9 inspecting the vehicle. Law enforcement and paramedics could be seen caring for at least one unidentified individual.