"At that time, he started to lunge toward, run aggressively toward Capitol Police officers", Pittman said.
The United States Capitol Building was placed on lockdown on Friday (April 2) due to an external security threat.
According to reports from Fox News and NBC, the suspect was shot after he rammed police and exited the auto wielding a knife.
Both the U.S. Senate and House of Representatives were not in session Friday as Congress is on recess.
An attack at the US Capitol complex in Washington DC has left one police officer dead and another in hospital with injuries.
The U.S. Capitol Police Department says one of its officers has died and another is injured after being rammed by a vehicle outside the building Friday afternoon.
Streets surrounding the US Capitol and congressional office buildings were locked down, with dozens of police cars - marked and unmarked - raced toward America's legislative seat.
Since then security officials have said there is an ongoing threat from extreme-right groups and Trump supporters.
Security officials, including the Capitol Police and National Guard, were faulted for reacting slowly to the crowds who stormed the Capitol on January 6.
The Capitol Building was placed on lockdown Friday after a auto rammed into two Capitol Police officers near the Northern Barricade. Law enforcement is working to understand the motive behind this incident. Fencing that prevented vehicular traffic near that area was recently removed.
The entry point on Constitution Avenue where the vehicle struck the barricade is frequently used by senators and staff.
The officials could not discuss the matter publicly and spoke to the AP on condition of anonymity.
Video posted online showed a dark colored sedan crashed against a vehicle barrier and a police K9 inspecting the vehicle.
National Guard troops were mobilized and staff at the huge Capitol complex ordered to stay away from windows and seek cover after alerts went out over the incident.
It appears at least one injured party was transported by helicopter.
"Also, the Federal Bureau of Investigation has now responded to this incident. they will be carrying out their own inquiries, trying to understand how and why this happened".