The suspect stamped a knife and the police officer got out of the car before he was shot.
The capitol was locked and a National Guard team was deployed as the police were instructed to stay inside.
Two officers were hit by cars and taken to hospital.
In the footage taken from the scene, a helicopter flying overhead and two people with stretchers apparently transported to an ambulance were shown.
Observers said that senators and their staff came to the capital every day at the entrance of Constitution Street, where the car hit the roadblock.
But Congress is now exhausted, so most politicians are not in the capital complex today.
President Joe Biden left Washington early in the day to have Mary David retreat to Camp David.
However, some journalists, caregivers, and Capitol Hill employees are probably still on a capital basis.
Shortly after 13:00 (18:00 GMT) local time, the Capitol Police alert system sent an email instructing lawyers and staff to stay away from outside windows and doors. Everyone outside was instructed to search the cover.
The FBI’s Washington Field Office responded and is now helping the Capitol Police. US Attorney General also aware of the incident and is beingto CBS News.
The incident occurred almost three months after the deadly January riots in the capital.