The scientific panel said the anthrax used in mailings to news organizations and members of Congress was the Ames strain Bacillus anthracis, and spores from those letters shared "a number of genetic similarities" with spores in Ivins' flask. But the findings say the FBI did not fully explore other possible explanations for those similarities.  Ivins knew he was under suspicion by the FBI and committed suicide in July 2008 before any charges were filed against him. Ivins was involved in anthrax vaccine research at the U.S. Army Medical Research Institute for Infectious Diseases at Fort Detrick in Frederick, Maryland.  Paul Kemp, a lawyer who represented Ivins, said that since August 2008, the Justice Department has maintained it had a "smoking gun" in the case against Ivins, citing the flask.  "Their smoking gun just turned into smoke and mirrors," Kemp said of the report. "They said they had a smoking gun that would have convicted him (Ivins) in court and this report shows they didn't."  Kemp later added: "Over 200 people had access to the anthrax that came out of that flask."  In response to the report, the FBI said, while the scientific investigation could not pinpoint the source of the anthrax, it helped its agents and the Justice Department to focus resources and conclude that Ivins was behind the attacks.  "Ultimately, the late Dr. Bruce Ivins was determined to be the perpetrator of the deadly mailings. The FBI and Department of Justice were preparing for prosecution at the time of Dr. Ivin's death," the FBI said.  Ivins maintained his innocence up until his death, Kemp said, adding that Tuesday's report "just casts doubts" on the FBI's conclusion that his former client was responsible.  The FBI praised the report for highlighting the value of what the FBI called "microbial forensics," which it said "proved significant" in solving the case.
Using the available scientific evidence "it is not possible to reach a definitive conclusion" about the source of the anthrax used in the 2001 anthrax letter attacks which killed five people,