(NECN: Justin Michaels/AP) - A source tells NBC News that 34-year-old Miriam Carey, the woman killed in the Capitol car chase, had a history of mental illness.
The source apparently said she most recently believed that President Obama was stalking her.
The mother of a woman who was shot to death by police after a car chase that began when she tried to breach a barrier at the White House and ended outside the Capitol building said her daughter suffered from post-partum depression.
The harrowing chase Thursday unfolded between two U.S. landmarks, briefly shuttered the chambers where federal lawmakers were debating how to end a government shutdown and stirred fresh panic in a city where a gunman two weeks ago killed 12 people.
Two law enforcement officials identified the driver as 34-year-old Miriam Carey, of Stamford, Connecticut. She was traveling with a 1-year-old girl who avoided serious injury and was taken into protective custody. The officials spoke on condition of anonymity because they were not authorized to discuss an ongoing investigation.
Carey's mother, Idella Carey, told ABC News Thursday night that her daughter began suffering from post-partum depression after giving birth to her daughter, Erica, last August.
"A few months later, she got sick," she said. "She was depressed. ... She was hospitalized."
Idella Carey said her daughter had "no history of violence" and she didn't know why she was in Washington on Thursday. She said she thought Carey was taking Erica to a doctor's appointment in Connecticut.
Police said there appeared to be no direct link to terrorism and there was no indication the woman was even armed. Capitol Police Chief Kim Dine, whose officers have been working without pay as a result of the shutdown, called it an "isolated, singular matter."
Information from the Associated Press was used in this report.