“The guy was angry at authority, angry at the establishment,” one source said. “And so he’s in there basically getting hypnotized by the computer. Talk about brainwashing. This guy sat in his room for days at least three days straight, closed the door and just sat in front of his computer.”

NYPD spokesman Steve Davis told ABC News he cannot discuss specifics of the investigation, except to say that detectives are confident that Thompson was acting alone without specific direction from a terror leader elsewhere. That, however, just proves how dangerous such “lone wolves” are, Davis noted.

“The investigation is continuing,” Davis said. “The further we get into this we are confident that, if he were directly inspired or directly recruited by a known quantity, that would have come out by know. It’s pretty clear he was radicalized by himself. But in a way that’s more bothersome than the people that are recruited by the real deal because you can’t see these people.”