Relatives of the woman who was shot to death outside the U.S. Capitol after trying to ram her car through a White House barrier say she was a "carefree, loving, law-abiding citizen" and don't know why she was killed.
Speaking to reporters outside their Brooklyn home after returning from Washington to identify Miriam Carey's body, her sisters said they were "still very confused as to why Miriam is not alive."
She was struggling with postpartum depression, but "she was not walking around delusional," said sister Amy Carey.
"We don't know why Miriam ended up going to DC, we don't know if her depression contributed to her taking that ride," said Amy Carey. "We don't know what was in her mind at that time."
Amy Carey also said her sister was unarmed and police should have responded differently.
A federal law enforcement official says Miriam Carey had been under the delusion the president was communicating with her.
Interviews with some of those who knew the 34-year-old woman suggested she was coming apart well before she loaded her 1-year-old daughter into the car for the drive to Washington.
Carey had suffered a head injury in a fall and had been fired as a dental hygienist, according to her former employer.
The federal law enforcement official, who had been briefed about the investigation but was not authorized to discuss it publicly and spoke on condition of anonymity, said investigators were interviewing Carey's family about her mental state and examining writings found in her Stamford condominium.
"We are seeing serious degradation in her mental health, certainly within the last 10 months, since December, ups and downs," the official said. "Our working theory is her mental health was a significant driver in her unexpected presence in D.C. yesterday."
Carey believed President Barack Obama was communicating with her, the official said. "Those communications were, of course, in her head," the official said, adding that concerns about her mental health were reported in the last year to Stamford police.
Stamford Police Chief Jonathan Fontneau said his officers had gone to Carey's home in the past, though not in response to any crime. He gave no details.
The federal official said investigators believe that she drove straight to the nation's capital and that the violence unfolded immediately upon her arrival.
After ramming the barricades at the White House, the apparently unarmed Carey led police on a chase down Constitution Avenue to the Capitol, where she was shot in a harrowing chain of events that led to a brief lockdown of Congress. Carey's daughter escaped serious injury and was taken into protective custody.
Carey, who was originally from New York City, had a good relationship with her mother and sisters, one of whom is a retired NYPD sergeant, sources told NBC 4 New York. Police spoke with Carey's relatives at their Brooklyn and Staten Island homes Thursday.
Carey's family said they identified her body through a photo in Washington, D.C. Friday. They were still waiting for her body to be released.
Freddie Perrer lives next door to one of Carey's sisters in Brooklyn and said there were no obvious signs of personal issues or distress.
"I'd seen her one time, she was getting in the car, going back to Connecticut," he said. "She seemed normal. She had the baby, she was laughing. Everybody was laughing."
Carey's neighbors in Stamford were shocked to learn the driver's identity and see her gleaming black Infiniti wrecked outside the Capitol in TV footage.
Erin Jackson, her next-door neighbor on the building's ground floor, said Carey doted on her daughter, Erica, often taking the girl on picnics.
"She was pleasant. She seemed very happy with her daughter, very proud of her daughter," she said. "I just never would have anticipated this in a million years."
Experts say symptoms of postpartum depression include lack of interest in the baby; mood swings between sadness and irritability; scary thoughts of something bad happening to the baby; and, in severe cases, suicidal thoughts — but not delusions.
In contrast, a condition known as postpartum psychosis can come with hallucinations, paranoia and desires to hurt the child. But it is extremely rare and does not tend to last for a year, experts say.
"If it's just a case of postpartum depression, you usually don't see people hurting others or getting aggressive," said Dr. Ariela Frieder, a psychiatrist at New York's Montefiore Medical Center.
She said that some women who appear to have postpartum psychosis actually have a different mental illness — bipolar disorder.
Carey's former employer in Connecticut, dentist Barry Weiss, told NBC Connecticut that she was "an average employee."
"There were a few instances of her being headstrong, but generally she was an average employee," Weiss said. "She did her job and left at the end of the day."
Carey took some time off work after falling down a staircase and suffering a head injury. A few weeks after she returned to work, she was fired in August 2012 because she "could be a bit rough" and patients were complaining, according to Weiss.
Carey's family said there were other reasons she left the office, but did not elaborate.