Story highlights Investigation goes to New York City; Stamford, Connecticut

Police say suspect, a woman, was shot and killed

Car chase began near White House and ended near the Capitol

A young child was in the suspect's car and was later placed in protective custody

She had a 1-year-old child inside and apparently was unarmed.

Instead, the motorist's black Infiniti, according to authorities, itself became a weapon Thursday afternoon, first striking a security barrier and U.S. Secret Service officer near the White House before hurtling down some of the capital's most famous streets, police cruisers in pursuit.

Dramatic video taken minutes later near the U.S. Capitol showed the vehicle backing into a police vehicle before the chase resumed. Gunshots rang through the traffic circle. The motorist was shot by police just a few blocks away.

The woman died. The child was safe and in protective custody. Two officers were injured. Police vehicles were damaged.

And a city heretofore fixated on a partial government shutdown was left with unanswered questions.

Why did this happen? Why did the woman drive away from the White House and toward Capitol Hill?

While U.S. Capitol Police Chief Kim Dine said there appeared to be no evidence of terrorism, Metropolitan Police Department Chief Cathy Lanier said, "This does not appear to be in any way an accident."

Officials, who called it an "isolated incident," were tight-lipped about the suspect and did not name her at an evening briefing.

The early hours of the investigation turned northward Thursday night.

A task force prepared to execute a search warrant at the woman's Stamford, Connecticut, residence, law enforcement sources said. Police and bomb squad units surrounded an apartment complex.

Authorities wanted to speak with the suspect's relatives in Brooklyn, New York, but were turned away, federal law enforcement sources told CNN.

The chase created a chaotic scene of blaring sirens, locked-down lawmakers and bystanders hitting the dirt.

House and Senate sessions were immediately suspended, with legislators ordered to take cover and keep away from windows. Police also closed Pennsylvania Avenue in front of the White House.

Photos: Photos: Shooting on Capitol Hill Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A police officer and K9 inspect the scene after a car chase and reports of gunshots fired outside of the Hart Senate Office Building on Captiol Hill on Thursday, October 3 in Washington. Police said the U.S. Capitol was put on security lockdown. Hide Caption 1 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Rescue personnel stand around a smashed U.S. Capitol Police cruiser near the Capitol. Hide Caption 2 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Police evidence markers are placed at the scene outside the U.S. Capitol.

Hide Caption 3 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – First responders put a police officer on a stretcher after pulling him out of a wrecked cruiser. Hide Caption 4 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Emergency personnel put an unidentified police officer on a stretcher. Hide Caption 5 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – People take cover as gunshots are heard. Hide Caption 6 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Police respond to the shooting. Hide Caption 7 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Secret Service agents, as well as other law enforcement officers, gather at the White House entrance. Hide Caption 8 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Sen. Bernie Sanders speaks on the phone at the Capitol. Hide Caption 9 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Police secure the scene. Hide Caption 10 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Police stand guard at the Capitol. Hide Caption 11 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Law enforcement personnel move toward the incident scene. Hide Caption 12 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Police run near 2nd Street NW and Constitution Avenue in Washington on October 3. Hide Caption 13 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A Capitol Police officer runs through the first-floor lobby in the Senate wing on Capitol Hill. Hide Caption 14 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A view of the scene from Maryland Avenue. Hide Caption 15 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A U.S. Capitol Police Officer stands guard in front of the Capitol. Hide Caption 16 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A damaged U.S. Capitol Police car is seen after the car chase and reported shooting incident. Hide Caption 17 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A Senate staffer watches as Capitol Hill Police respond to reports of gunshots fired outside of the Hart Senate Office Building near the U.S. Capitol. Hide Caption 18 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Pedestrians wait by temporary barriers after the area around the White House was put on lockdown. Hide Caption 19 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A member of the Secret Service counterassault team walks past the entrance of the White House. Hide Caption 20 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – U.S. Capitol Police respond to reports of shots fired. Hide Caption 21 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A police officer runs after reports of shots being fired. Hide Caption 22 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Capitol Hill Police respond to reports of gun shots. Hide Caption 23 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A Capitol Police officer directs people away from a door on Capitol Hill. Hide Caption 24 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Sen. Jack Reed watches as a Capitol Hill police officer puts on a his body armor after the shooting was reported. Hide Caption 25 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Capitol Hill Police officers gather in response to the shooting. Hide Caption 26 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Members of the media watch as Capitol Hill Police respond to the report of shots fired. Hide Caption 27 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – People take cover as gunshots were heard. Hide Caption 28 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A member of the U.S. Secret Service counter-assault team patrols the grounds of the White House October 3 in Washington. Hide Caption 29 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A Secret Service vehicle joins law enforcement officers riding on horseback. Hide Caption 30 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Capitol Police respond to reports of shots fired on Capitol Hill. Hide Caption 31 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – Police gather near the scene on Capitol Hill. Hide Caption 32 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – People run for cover as police converge to the site of a shooting. Hide Caption 33 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A man runs for cover as a police officer takes position at the site of a shooting. Hide Caption 34 of 35 Photos: Photos: Shooting on Capitol Hill Shooting on Capitol Hill – A police officer runs while reacting to a call of shots fired. Hide Caption 35 of 35

JUST WATCHED Track car chase that ended near Capitol Replay More Videos ... MUST WATCH Track car chase that ended near Capitol 02:55

JUST WATCHED Capitol Hill: Scenes of panic Replay More Videos ... MUST WATCH Capitol Hill: Scenes of panic 01:58

JUST WATCHED House stops abruptly Replay More Videos ... MUST WATCH House stops abruptly 00:19

The chase began near the White House.

A U.S. Secret Service source said when the woman drove up to a barrier at the 15th and E street checkpoint, she was approached by Secret Service officers who did not recognize her car.

The motorist hurriedly tried to drive away, executed a three-point turn, struck the barrier and backed into an officer before driving away, the source told CNN.

Police said the car sped down Pennsylvania Avenue toward the Capitol, where security vehicles stopped it at Garfield Circle.

Frank Schwing, a Washington resident who was near the area, said officers "came out with their guns drawn" and approached the suspect's vehicle.

"At that point, the driver slammed into reverse, slammed into a cruiser, did a 180 (degree turn), took off," Schwing told CNN, adding, "at that point, there were a half dozen or so shots fired," apparently all by small arms from police.

Video footage by other witnesses showed the black vehicle then careening around a nearby traffic circle with a police car in close pursuit and then headed away. Shortly afterward, the car crashed into security barriers a few blocks away, witnesses said.

Lanier said more shots were fired after the vehicle stopped, and the woman was hit several times. The driver was later pronounced dead, Lanier said.

According to multiple sources, there was no reason so far to believe that the woman fired any shots or even had a weapon. Officers did not know a child was inside during the chase, officials said.

Lanier, citing the lengthy pursuit, rammed vehicles and an attempt to breach two security perimeters, said the driver's actions did not appear to be accidental.

Security perimeters at the White House and Capitol worked, Lanier told reporters.

"They did exactly what they were supposed to do," she said.

A Capitol Police officer whose vehicle crashed during the chase also was hurt, authorities said. The officer was released from a local hospital Thursday night. The Secret Service did not release information about its injured agent.

Authorities lauded the action of police -- some of whom aren't being paid -- who responded to the incident.

Because of the government shutdown, U.S. Capitol Police aren't receiving a paycheck, although they will receive checks once appropriations are restored.

In Congress, a Capitol Police bulletin said reports of gunshots required "all occupants in all House office buildings to shelter in place."

"Close, lock and stay away from external doors and windows," the bulletin said. Authorities later lifted the lockdown, with police saying they believed the incident was isolated.

President Barack Obama was briefed on the situation, which occurred on the third day of a government shutdown due to a stalemate in Congress over government funding.

"The timing on this was really kind of scary," said Republican Rep. Blake Farenthold of Texas. "Capitol Hill police are at a lower personnel level because of the shutdown."