A troubled Army bio-weapons scientist was the only person responsible for the 2001 anthrax attacks that killed five people and injured 17 others, the Department of Justice said today.
At a news conference and in hundreds of pages of court documents unsealed today, investigators said they zeroed in on Bruce Ivins, who committed suicide last week, after learning that he had custody of a batch of anthrax that had "genetic mutations" identical to the type used in the attacks.
Ivins allegedly also sent an e-mail warning that terrorists had access to anthrax, using language similar to that found in handwritten notes sent to media and government officials along with anthrax spores, just a few days before the antrhax letters were sent, according to the documents
After a seven-year investigation, which focused for much of the time on the wrong suspect, the Department of Justice today declared the case solved. After presenting a largely circumstantial case against Ivins, U.S. Attorney Jeffrey Taylor said he was confident that Ivins was the only person responsible for the attacks, adding, "We regret that we will not have the opportunity to present evidence to the jury."
Taylor said that a scientific breakthrough in 2005 allowed investigators to trace the anthrax used in the attacks to a single flask of anthrax that was under Ivins' custody at an Army lab in Fort Detrick, Md. Investigators focused on Ivins as the main suspect in 2007, after eliminating nearly 100 others who had access to the flask as possible suspects, he said.
Lawyers for Ivins lashed out at the government's case, saying the evidence is thin and that Ivins was a respected scientist.
"The government released search warrants – investigative tools designed to discover evidence, not to serve as evidence and treated these warrants as smoking guns," lawyers from Venable LLP said in a statement. "The government's press conference was an orchestrated dance of carefully worded statements, heaps of innuendo and a staggering lack of real evidence – all contorted to create the illusion of guilt by Dr. Ivins."
But the documents unsealed today say Ivins struggled with depression and paranoia for years, and became increasingly troubled as investigators closed in.
Affidavits also say the FBI suspected that Ivins gave the bureau false anthrax samples to mislead investigators and was "unable to give investigators an adequate explanation for his late-night laboratory work" around the time the anthrax letters were sent, according to the documents.
Ivins sent an e-mail to a recipient whose name was redacted a few days before the anthrax attacks, warning that Osama bin Laden and other terrorists "for sure have anthrax."
Thomas Dellafera, an investigator for the U.S. Postal Inspection Service, which conducted the probe with the FBI, said Ivins wrote in the e-mail that the terrorists have "just decreed death to all Jews and all Americans."
That language, investigators claim, was similar to that of the anthrax letters, which warned, "WE HAVE THIS ANTHRAX ... DEATH TO AMERICA ... DEATH TO ISRAEL."
Investigators also reportedly traced the envelopes used to mail the anthrax spores to the Fort Detrick, Md., post office.
The government's presentation of its case came as the U.S. Army Medical Research Institute of Infectious Diseases held a memorial service for Ivins, which was attended by family and co-workers.
An Army official desribed the hour-long service, which was closed to the public, as "very emotional."
Ivins' co-workers who spoke at the service described him as a "brilliant scientist" and "a mentor" who was admired for his intellect and for his "quirky sense of humor," the Army official said.
The court documents released today painted a much darker portrait of Ivins.
One affidavit, from a postal inspector, said that Ivins, a 62-year-old anthrax researcher, was suffering from serious mental health problems in the months before the attack and told a co-worker he had "incredible paranoid, delusional thoughts at times" and feared that he might not be able to control his behavior.
Ivins died last week of a drug overdose as prosecutors were preparing to charge him with murder in connection with the anthrax letters. His lawyer has said that Ivins would have been found not guilty had he lived.
Federal law enforcement sources said the FBI is ready to close its multimillion dollar investigation into the 2001 anthrax mailings.
The release of the documents came hours after authorities briefed the victims of the attacks.
The government's investigation traced the anthrax sent in 2001 to members of the news media and government officials, to the same batch of that strain of the deadly virus. The affidavits say Ivins was the sole custodian of that batch, though those close to him have said that as many as 30 other scientists may have had access to it.
In the days before the two batches of letters were sent, Ivins reportedly spent an unusual amount of time in the lab after hours, on a few occasions staying past midnight, the affidavit says.
When asked in 2005 why he was spending so much time in the lab, Ivins reportedly told investigators that "home was not good" and that he went to the lab to escape.
Asked for samples of the anthrax from his lab, Ivins apparently attempted to mislead investigators, the affidavit claims, by providing the wrong samples.
The documents are the latest twist in a seven-year-long investigation that has drawn criticism of the FBI, which focused for a time on the wrong man.
The government recently agreed to pay nearly $6 million to Steven Hatfill, a former Fort Detrick researcher, who was named a "person of interest" in the case.
When the Justice Department made the announcement that effectively exonerated Hatfill, investigators waited for Ivins to react.
Weeks later, Ivins allegedly began making threats during a therapy session. Jean Duley, who had been Ivins' social worker in therapy sessions, was convinced he might try to kill her and others.
She recently went to court seeking protection from Ivins. During a hearing on the matter, she described a chilling July 9 group counseling session. "He was extremely agitated, out of control," she said.
The evidence against Ivins likely will never be tested at a trial and some have been skeptical of the FBI's case, particularly in light of the government's focus on Hatfill, who was never charged.
The FBI used new DNA forensic techniques to link the anthrax spores used in the attack to the flask Ivins reportedly controlled. But that new technology has never been used -- or tested -- in a court of law.
So far, the FBI has not firmly placed Ivins at the sites where the anthrax letters were mailed, which include Princeton, N.J.
ABC News' Luis Martinez contributed to this report.