Miriam Carey pictured in a Facebook photo

Authorities investigating why a Connecticut woman rammed barricades and led police on a chase near the U.S. Capitol found medications in her apartment to treat schizophrenia and other mental disorders, a law enforcement source briefed on the investigation said Friday.

The woman was identified by law enforcement sources as Miriam Carey, 34. She was shot dead Thursday in the incident, which played out in one of the most heavily policed places in the world, temporarily locked down Congress and sparked anxiety among tourists and staffers alike.

Two law enforcement officers were injured. Police say Carey rammed barricades and police cruisers and sped down Pennsylvania Avenue before crashing.

She apparently did not have a weapon, but did have a 1-year-old child in the car with her. The child emerged from the chaos unharmed, officials said.

Authorities who searched the apartment in Stamford, Connecticut, found one medication to treat schizophrenia and bipolar disorder, and another that is an antidepressant, according to the source.

A law enforcement source involved in the investigation said Thursday that the woman's boyfriend had told police last winter that she appeared to be delusional.

Authorities have not officially linked the incident to mental illness or any other cause.

The area around Carey's apartment remained cordoned off Friday.

History of concerns

Carey's boyfriend contacted police in December saying he feared for the safety of their child, who was 4 months old at the time, according to a law enforcement source involved in the investigation. The boyfriend said the woman was acting delusional, claiming the president had placed Stamford under lockdown and that her house was under electronic surveillance, the source said.

He told police that she was suffering from post-partum depression, was having trouble sleeping and was on medication. Carey underwent a mental health evaluation, said the source, who added that the boyfriend has been questioned by federal authorities about Thursday's events.

The source told CNN that Carey left a letter addressed to the boyfriend at her apartment and that it appeared to contain white powder. The letter was being tested for hazardous substances.

A car chase, gunshots

Thursday's drama began around 2 p.m., when the woman steered a black Infiniti near the White House, a U.S. Secret Service source said. She drove up to a barrier at the 15th and E street checkpoint and was approached by Secret Service officers. She hurriedly made an erratic three-point turn, striking the barrier and backing 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.

The woman slammed the car into reverse, crashing into a police cruiser, and tried to get away. At that point officers began firing, a witness said.

Dramatic video footage by a videographer for Alhurra TV, a Middle Eastern news outlet financed by the U.S. government, showed the black vehicle then speeding around a nearby traffic circle with a police car in close pursuit and then heading away. The car crashed into more security barriers a few blocks later, witnesses said.

More shots were fired after the vehicle stopped, and the woman was hit several times, said Metropolitan Police Department Chief Cathy Lanier. Carey was later pronounced dead, Lanier said. Two officers were injured.

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

Chaos and a child in the car

Inside the woman's car was a 1-year-old child, who was not harmed. The child was taken into protective custody, officials said. Officers didn't know there was a child inside the woman's car during the chase, officials said. Also, the early investigation revealed that there was no evidence that the woman had a gun or fired a shot.

The bedlam from the fatal chase reverberated throughout a U.S. Capital already shaken by the recent mass shooting at the Navy Yard in the city and on edge due to tensions over the showdown over shutting down the federal government.

Authorities locked down the Capitol building and other government facilities in the area.

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.

Sirens blared as people in and around government office buildings reported hearing gunshots. Bystanders hid in fear.

Shemaiah Ofori-Attah and her hsuband, Edmund, at first thought the speeding black car and sirens were part of a motorcade.

"Then when we heard the gunshots we knew this was something serious, so we just dropped to the ground," she said.

Danny Farkas, the Alhurra videographer, captured the scene. He said he had a fleeting thought that perhaps the driver had explosives in the car.

"I was surprised at the movie-like quality of what was going on in front of me," he told CNN's "New Day."

Michael Pearson and Lateef Mungin report and wrote from Atlanta; Joe Johns reported from Washington; CNN's Deborah Feyerick, Evan Perez, Dana Bash, Mike Ahlers, Ted Barrett, Jake Tapper, John King, Aaron Cooper, John Auerbach, Gabe Lamonica, Brian Todd, Martina Stewart, Rose Arce, Tom Cohen and Dan Merica contributed to this report.