(Photo: Facebook via MiriamCarey)

Connecticut resident Miriam Carey caused the brief lockdown of Capitol Hill Thursday afternoon that began after she rammed her black Infiniti sedan into security barriers near the White House and led police on a car chase along Pennsylvania Avenue before being shot to death by the police.

As details of the shooting began to trickle through the media — particularly the fact that Carey had her 1-year-old daughter with her at the time — what was first speculated as possible terrorist activity soon morphed into a peculiar incident.

So, who is Miriam Carey? Here's what we know:

According to a CNN report, during a search of her apartment, authorities found medications to treat schizophrenia and other mental disorders. A law enforcement source told the network that her boyfriend contacted the police in December out of fear for the safety of their child because she had been "acting delusional, claiming the president had placed Stamford under lockdown and that her house was under electronic surveillance." 
The source also said that Carey left a letter to her boyfriend in her apartment that "appeared to contain white powder" now being tested for hazardous substances.
Carey's mother, Idella Carey, who spoke with ABC News, said that her 34-year-old daughter was suffering from postpartum depression after having her daughter Erica last August. Erica was taken from the car and placed in "protective custody," police confirmed.

Described as a "non-political person" and "always happy" by Dr. Steve Oken, her boss of eight years, Carey was a dental hygienist with no criminal record in Connecticut and no pending criminal actions.

"I would never in a million years believe that she would do something like this," Oken told ABC News. "It's the furthest thing from anything I would think she would do, especially with her child in the car. I am floored that it would be her."

One neighbor who did not know Miriam well, but crossed paths with her frequently, told the Chicago Tribune that she "pretty much kept to herself." Another neighbor said that Miriam "absolutely" had mental illnesses.

Neither Miriam's mother nor her sister, Amy Carey, knows why Miriam was in Washington, D.C. on Thursday. Idella Carey said she believed Miriam was bringing the young girl to a doctor's appointment in Connecticut that afternoon, while Amy told reporters that Miriam had been in Connecticut two days before the incident.

"I spoke to her," Amy told the Chicago Tribune. "I don't know what's happening. I can't answer any more."

BET National News - Keep up to date with breaking news stories from around the nation, including headlines from the hip hop and entertainment world. Click here to subscribe to our newsletter.