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.