(WASHINGTON) -- A woman believed to be a dental hygienist from Stamford, Conn., was shot dead by police Thursday after allegedly attempting to ram the White House gates and leading authorities on a high-speed chase to the U.S. Capitol, officials said.
The related gunfire sent senators and staffers scrambling inside the Capitol, which was put under lockdown.
Authorities believed the dead suspect was Miriam Carey, 34, according to a spokesman for Carey's family. Authorities said she had a history of mental health issues, and her mother told ABC News she suffered from post-partum depression.
A female child approximately 1-year-old was found unhurt in the suspect's car, authorities said.
A police bomb squad was outside Carey's Stamford address Thursday night. Police there said they were awaiting a search warrant from Washington, though 50 people from the apartment building already were being evacuated for the night. In addition, anyone who walked into the hallway outside the suspect's apartment was going through a decontamination procedure out of an abundance of caution, officials said.
Police said there were no weapons found in Carey's car.
A U.S. Capitol Police officer injured during Thursday's events was treated and released at MedStar Washington Hospital Center, the hospital said later in the evening.
The incident began at approximately 2:12 p.m. when a black Infiniti rammed a barrier outside the White House at 15th Street and Pennsylvania Avenue NW. The car was chased to 2nd Street and Constitution Avenue NW, police said.
"[The suspect] circled monuments in front of Capitol Hill twice while being pursued. Then she headed toward the Capitol where Capitol Hill police and Secret Service opened fire and shot her," said Senate Sergeant at Arms Terry Gainer.
At one point, a group of at least five cops surrounded the woman's stopped car with their guns drawn. The suspect, driving a black, two-door Infiniti sedan, appeared not to heed their commands and sped off, nearly running over a couple of officers, as seen in a video obtained by ABC News.
With their pistols drawn, cops "were shouting at the driver," Frank Schwing, a furloughed Commerce Department employee, told ABC News. "At that point, the driver put [the car] in reverse, drove back, and slammed into a cruiser."
The officers ran back to their cars and began chasing the woman again toward the Capitol.
The suspect's car rammed a Capitol Police vehicle and was stopped by an automated barrier near the Hart Senate Building, police said. Officers were authorized to shoot at the car.
Metropolitan Police Chief Cathy Lanier said shots were fired at several points during the chase.
Ed Donovan of the Secret Service said the car was initially stopped at an outer perimeter checkpoint of the White House and no shots were fired at the White House.
In fleeing the White House scene, the suspect hit a Secret Service officer with her car, Donovan said.
During the pursuit, the woman struck several cars a Capitol Police officer was injured in a traffic accident involving an automated barricade during the chase.
"We heard pops that sounded like shots," Sen. Bob Casey, D-Pa., told ABC News.
"We heard shots. They told us to get behind a car," Sen. Sherrod Brown, D-Ohio, said as he re-entered the Capitol building just moments before it was placed on lockdown.
There is "no information this is related to terrorism or this anything other than an isolated incident," Capitol Police Chief Kim Dine told reporters.
An initial alert to lawmakers and staffers came around 2:25 p.m. A half hour later at 2:55 p.m., the lockdown was lifted. The Supreme Court was also briefly closed following reports of gunfire.
"Close, lock and stay away from external doors and windows. Take annunciators, emergency supply kits and escape hoods; and move to your office's assigned shelter in place location or the innermost part of the office away from external doors or windows," Capitol Police told congressional staffers staffers in an email.
The Capitol this week is the center of a contentious political battle over an ongoing government shutdown.
Additional media: Lockdown Lifted After Reports of Shots Outside US Capitol
Copyright 2013 ABC News Radio