WASHINGTON - After seven frustrating years probing the deadly 2001 anthrax mailings, the FBI closed the case Friday, concluding a mentally unhinged government researcher acted alone in the attacks that killed five people and unnerved Americans nationwide.
Many details of the case have been known, but newly released FBI documents paint a fuller portrait of Dr. Bruce Ivins as a troubled scientist whose career was teetering toward failure at the time the letters were sent.
As the United States responded to the mailings, his work was given new importance by the government and he was even honored for his efforts on anthrax.
The documents also describe what investigators say was Ivins' bizarre, decades-long obsession with a sorority. The letters were mailed from a mailbox near the sorority's office in Princeton, N.J.
The letters were sent to lawmakers and news organizations as the nation reeled in the aftermath of the Sept. 11, 2001, terror attacks.
The FBI and Justice Department announced the decision closing the case while disclosing reams of evidence collected. Officials also released a nearly 100-page summary of their findings.
The document said Ivins made comments to a former colleague that showed "immediately prior to the anthrax letter attacks, his life's work was in jeopardy."
Ivins killed himself in 2008 as prosecutors prepared to indict him in the attacks. He had denied involvement, and his family and some friends have continued to insist he was innocent.
Authorities say Ivins cast suspicion on his colleagues and tried numerous forms of subterfuge.