The woman, whose name was not available, told The (Newark) Star-Ledger that Dzhokhar Tsarnaev, 19, and his brother Tamerlan, 26, were "great people" and she would have never expected them to be involved in the bombing.
"They are smart -- I don't know what's gotten into them," she said.
About a dozen FBI agents showed up at the woman's apartment in West New York Friday, apparently with a search warrant. They were seen bringing official evidence boxes into the residence a short time later.
It was not known what the agents might have seized from the residence. The police chief of West New York said the woman was cooperating with investigators.
"I'm not okay -- no one is okay right now," the woman added when asked by The Star-Ledger reporter if she was holding up under the sudden stress. "I'm hurt for everyone who has been hurt. I'm sorry for all the people who are hurt and for all the people who lost their lives."