This story first appeared on the ProPublica website. The story is a joint project with ProPublica, PBS Frontline and McClatchy. The story will air on Frontline on Oct. 11. Check local listings.
Months after the anthrax mailings that terrorized the nation in 2001, and long before he became the prime suspect, Army biologist Bruce Ivins sent his superiors an email offering to help scientists trace the killer.
Already, an FBI science consultant had concluded that the attack powder was made with a rare strain of anthrax known as Ames that's used in research laboratories worldwide.
In his December 2001 email, Ivins volunteered to help take things further. He said he had several variants of the Ames strain that could be tested in "ongoing genetic studies" aimed at tracing the origins of the powder that had killed five people. He mentioned several cultures by name, including a batch made mostly of Ames anthrax that had been grown for him at an Army base in Dugway, Utah.
Seven years later, as federal investigators prepared to charge him with the same crimes he'd offered to help solve, Ivins, who was 62, committed suicide. At a news conference, prosecutors voiced confidence that Ivins would have been found guilty. They said years of cutting-edge DNA analysis had borne fruit, proving that his spores were "effectively the murder weapon."
To many of Ivins' former colleagues at the germ research center in Fort Detrick, Md., where they worked, his invitation to test the Dugway material and other spores in his inventory is among numerous indications that the FBI got the wrong man.
What kind of murderer, they wonder, would ask the cops to test his own gun for ballistics?
To prosecutors, who later branded Ivins the killer in a lengthy report on the investigation, his solicitous email is trumped by a long chain of evidence, much of it circumstantial, that they say would have convinced a jury that he prepared the lethal powder right under the noses of some of the nation's foremost bio-defense scientists.
PBS' Frontline, McClatchy and ProPublica have taken an in-depth look at the case against Ivins, conducting dozens of interviews and reviewing thousands of pages of FBI files. Much of the case remains unchallenged, notably the finding that the anthrax letters were mailed from Princeton, N.J., just steps from an office of the college sorority that Ivins was obsessed with for much of his adult life.
But newly available documents and the accounts of Ivins' former colleagues shed fresh light on the evidence and, while they don't exonerate Ivins, are at odds with some of the science and circumstantial evidence that the government said would have convicted him of capital crimes. While prosecutors continue to vehemently defend their case, even some of the government's science consultants wonder whether the real killer is still at large.
Prosecutors have said Ivins tried to hide his guilt by submitting a set of false samples of his Dugway spores in April 2002. Tests on those samples didn't display the telltale genetic variants later found in the attack powder and in sampling from Ivins' Dugway flask.
Yet, records discovered by Frontline, McClatchy and ProPublica reveal publicly for the first time that Ivins made available at least three other samples that the investigation ultimately found to contain the crucial variants, including one after he allegedly tried to deceive investigators with the April submission.
Paul Kemp, who was Ivins' lawyer, said the government never told him about two of the samples, a discovery he called "incredible." The fact that the FBI had multiple samples of Ivins' spores that genetically matched anthrax in the letters, Kemp said, debunks the charge that the biologist was trying to cover his tracks.
Asked about the sample submissions, as well as other inconsistencies and unanswered questions in the Justice Department's case, lead federal prosecutor Rachel Lieber said she was confident that a jury would have convicted Ivins.
"You can get into the weeds, and you can take little shots of each of these aspects of our vast, you know, mosaic of evidence against Dr. Ivins," she said in an interview. But in a trial, she said, prosecutors would have urged jurors to see the big picture.
"And, ladies and gentlemen, the big picture is, you have, you know, brick upon brick upon brick upon brick upon brick of a wall of evidence that demonstrates that Dr. Ivins was guilty of this offense."
Scientists who worked on the FBI's case do not all share her certainty. Claire Fraser-Liggett, a genetics consultant whose work provided some of the most important evidence linking Ivins to the attack powder, said she would have voted to acquit.
"I don't know how it would have been possible to convict him," said Fraser-Liggett, the director of the University of Maryland's Institute for Genome Sciences. "Should he have had access to a potential bio-weapon, given everything that's come to light? I'd say no. Was he just totally off the wall, from everything I've seen and read? I'd say yes.
"But that doesn't mean someone is a cold-blooded killer."
The Justice Department formally closed the anthrax case last year. In identifying Ivins as the perpetrator, prosecutors pointed to his deceptions, his shifting explanations, his obsessions with the sorority and a former lab technician, his penchant for taking long drives to mail letters under pseudonyms from distant post offices and, after he fell into drinking and depression with the FBI closing in, his violent threats during group therapy sessions. An FBI search of his home before he died turned up a cache of guns and ammunition.
Most of all, though, prosecutors cited the genetics tests as conclusive evidence that Ivins' Dugway spores were the parent material to the powder.
Yet, the FBI never could prove that Ivins manufactured the dry powder from the type of wet anthrax suspensions used at Fort Detrick. It couldn't prove that he scrawled letters mimicking the hateful rhetoric of Islamic terrorists. And it couldn't prove that he twice slipped away to Princeton to mail the letters to news media outlets and two US senators; it could prove only that he had an opportunity to do so undetected.
The $100 million investigation did establish that circumstantial evidence could mislead even investigators armed with unlimited resources.
Before focusing on Ivins, the FBI spent years building a case against another former Army scientist. Steven Hatfill had commissioned a study on the effectiveness of a mailed anthrax attack and had taken ciprofloxacin, a powerful antibiotic used to treat or prevent anthrax, around the dates of the mailings. Then-Attorney General John Ashcroft called Hatfill a "person of interest," and the government eventually paid him a $5.8 million settlement after mistakenly targeting him.
Ivins' colleagues and some of the experts who worked on the case wonder: Could the FBI have made the same blunder twice?