Yet Ivins stayed on the job at the military lab at Fort Detrick, Md. He also managed to buy guns and pass a background check.
As the FBI closed in on its top suspect, Ivins grew more unstable. He killed himself last week, more than a year after the FBI had gathered the primary evidence held up Wednesday as proof of his guilt.
Privacy concerns, bureaucratic loopholes, the demands of a criminal investigation - all combined to let Ivins keep his job and stay out of jail for years. And in the high-security lab until last November.
Or was it just that the government's evidence was too weak to act? That's what Ivins' attorney says.
"If it's such earth-shattering stuff, what's been going on since 2005?" Paul F. Kemp asked Wednesday after the government made its case with a news conference and a pile of documents. "Why is he on the street if they think it's that important?"
That question goes beyond the criminal investigation. It goes to the heart of how secure the nation's nearly 1,400 biological defense labs are and whether the estimated 14,000 scientists working with deadly toxins are being screened for the kind of mental illness Ivins exhibited.
The Army Medical Research Institute of Infectious Diseases, known as USAMRIID, follows strict security measures meant to weed out troubled scientists. It has offered no explanation for why Ivins was allowed to work with some of the world's most dangerous toxins while taking antidepressants and receiving counseling to control his inner demons.
"The thinking now by the psychiatrist and counselor is that my symptoms may not be those of a depression or a bipolar disorder, they may be that of a 'Paranoid Personality Disorder,' " he wrote in a July 2000 e-mail included in government documents released Wednesday.
"I get incredible paranoid, delusional thoughts at times, and there's nothing I can do until they go away, either by themselves or with drugs," he wrote that August.
