Decades after anthrax attacks, some still wonder if real killer is at large

WASHINGTON - Months after the anthrax attacks of 2001, government scientist Bruce Ivins offered to help investigators trace the origins of the deadly powder that had spread through the mail, killing five people. 

Years later, Ivins would be named as the sole suspect in the FBI’s investigation of "Amerithrax," the biggest biological attack in U.S. history. 

Ivins, an Army bio-defense researcher, was never charged with the crime. He committed suicide in July 2008, intentionally overdosing on Tylenol as the Justice Department was preparing to indict him for the attacks. He was 62 years old. 

Ivins had denied involvement, and his lawyer and some colleagues have maintained he was an innocent man hounded to self-destruction. In the years since his death, new evidence has cast doubt on the FBI’s case. 

Who was Bruce Ivins? 

Dig deeper:

According to NPR, Ivins worked on anthrax vaccines at the government's Fort Detrick lab in Frederick, Maryland. He was involved in testing samples from the deadly anthrax letters. 

"He worked exceptionally hard after '01, exhausted himself with the amount of work in his lab. Absolutely exhausted. He was processing thousands of samples a week," Dr. Martin Hugh-Jones, an epidemiologist, told NPR in 2008. 

Ivins was a Red Cross volunteer and a musician at his church. When the FBI named Ivins as the suspect, the news stunned many colleagues and friends who said he wasn’t capable of such a heinous act. 

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But others remember him differently. Documents showed Ivins had received psychiatric treatment before his suicide, and that a social worker had a protective order against him for stalking and threatening to kill her, according to NBC News. 

"It makes sense, what the social worker said," his estranged brother Tom Ivins said at the time. "He considered himself like a god."

According to The Associated Press, Ivins emailed himself in 2007 and said he knew who the killer was. He sent it Sept. 7, 2007, telling himself, ‘Yes! Yes! Yes! I finally know who mailed the anthrax letters in the fall of 2001. I’ve pieced it together." The email to himself didn’t name the suspect. 

FBI’s ‘Amerithrax’ investigation

By the numbers:

The Amerithrax Task Force, a full-time team of 25-30 investigators, conducted more than 10,000 witness interviews and reviewed more than 6,000 pieces of evidence, according to the FBI. There were 5,750 grand jury subpoenas tied to the case, with 5,730 environmental samples taken from 60 sites. 

The other side:

Two separate reports found faults with the FBI’s anthrax investigation, though neither report concluded Ivins was innocent or didn’t act alone. 

A 77-page report from the Government Accountability Office said the FBI’s research used flawed scientific methods. The National Research Council said federal investigators overstated the scientific case against Ivins, but that the evidence was consistent with the FBI’s conclusions.

A 2011 investigation by ProPublica, PBS Frontline and McClatchy found case documents that contradicted some evidence the government said would convict Ivins. 

What they're saying:

Investigators have acknowledged the evidence is all circumstantial, but the FBI still believes they had the right guy. 

They said Ivins was in possession of a batch of anthrax that had "genetic mutations" identical to the type used in the attacks, according to ABC News. 

Ivins allegedly also sent an e-mail warning that terrorists had access to anthrax. In the email, he reportedly used language similar to what was used in the anthrax letters. The email was sent just days before the attacks.  

"Our conclusions weren’t based solely on the science but the full evidence before us," an FBI spokesperson told The Associated Press in 2014. 

The FBI formally closed the case in 2010. According to ProPublica, years later, "even some of the government’s science consultants wonder whether the real killer is still at large."

What happened in the anthrax attacks? 

The backstory:

Several letters containing anthrax spores were mailed across the U.S. in October and November 2001, shortly after the nation was rocked by 9/11. News media and senators’ offices were among the anthrax letter targets. 

Five people died in October and November 2001 from anthrax inhalation or exposure linked to the letters. They were a Florida photo editor, two postal workers in Washington, a hospital employee in New York City and a 94-year-old woman in Oxford, Connecticut. Seventeen others were sickened.

Postal facilities, U.S. Capitol buildings and private offices were shut for inspection and cleaned by workers in hazardous materials suits from Florida to New York and elsewhere.