FBI said to have stalked Ivins' family

Past investigations backfired
In the 1996 Atlanta Olympic park bombing that dragged Jewell into the limelight, the security guard became the focus of the FBI probe for three months, after initially being hailed as a hero for moving people away from the bomb before it exploded.

The bomber turned out to be anti-government extremist Eric Rudolph, who also planted three other bombs in the Atlanta area and in Birmingham, Ala. Those explosives killed a police officer, maimed a nurse and injured several other people.

In another case, the FBI used as evidence the secrets that a person tells a therapist.

In the Wen Ho Lee case, Lee became the focus of a federal probe into how China may have obtained classified nuclear warhead blueprints. Prosecutors eventually charged him only with mishandling nuclear data, and held him for nine months. In what amounted to a collapse of the government’s case, prosecutors agreed to a plea bargain in which Lee pleaded guilty to one of 59 counts.

In 2004, the FBI wrongly arrested lawyer Brandon Mayfield after the Madrid terrorist bombings, due to a misidentified fingerprint. The Justice Department’s internal watchdog faulted the bureau for sloppy work. Spanish authorities had doubted the validity of the fingerprint match, but the U.S. government initiated a lengthy investigation, eventually settling with Mayfield for $2 million.

More from msnbc.com U.S. steps up fight against illegal crossings |   Video Opinion: Tiger must address crash — and affair rumors It's a snap! Travel photo of the week Vote: Who do you think is person of year?   Slideshow: The month in space photos On Twitter: Breaking news updates | Weird and wild

MORE FROM SECURITY

Security Section Front

Tracking smugglers along the Mexican border 570,000 9/11 pager messages released U.S. offers $5 million reward for 'Bomb Man' New charges in Somali terror case Lawyer: Sept. 11 defendants want to air views Security Section Front   Add Security headlines to your news reader: