Photos taken at the scene show the woman’s dark-coloured Chevy four-door with a shot-out rear window and two bullet holes in the front windshield.
The woman, wearing a green jumper, was taken into custody.
The mayhem unfolded about 9.30am Wednesday (12.30am Thursday AEDT) when cops tried to stop the motorist, who was driving erratically along Independence Avenue, in Washington DC.
The driver, who has not yet been identified, made a U-turn and nearly struck some officers. It’s not clear when she rammed the Capitol police cruiser.
US Capitol Police spokeswoman Eva Malecki said the incident, which unfolded several blocks away from the White House, was not terror-related.
“This incident appears to be criminal in nature with no nexus to terrorism, and in addition the Capitol complex remains open to the public,” she told reporters.
Ms Malecki said shots were fired as cops tried to arrest the woman, but she didn’t say who fired. No one was hit by the bullets, which ABC News said were fired by Capitol police
Ms Malecki described the suspect as “erratic and aggressive” but said a motive is not yet known.