According to the National Academy of Science panel:
"The scientific link between the letter material and flask number RMR-1029 is not as conclusive as stated in the DOJ Investigative Summary,''
The FBI and DOJ stand by their verdict. And well they should. Unlike Steven Hatfill or Richard Jewell, Bruce Ivins is not around to fight back.
If the science the FBI used was shaky, then their whole case is toddering. They argue that the science was only a small part of their total investigation.
"The FBI has long maintained that while science played a significant role, it was the totality of the investigative process that determined the outcome of the anthrax case,'' the FBI and Justice Department said in a joint statement. "Although there have been great strides in forensic science over the years, rarely does science alone solve an investigation.''
The "totality of the investigative process" includes the sustained, wrong-headed pursuit of Richard Hatfill. Not the stuff to build confidence in the final conclusion if the science is shaky.
It's worth remembering that the investigation also hinges on one big assumption that is open to question:
Actually, the 96 page FBI report is predicated on the assumption that the anthrax letters attack was carried out by a "lone nut." The FBI report fails to entertain the possibility that the letters attack could have involved more than one actor. The FBI admits that about 400 people may have had access to Ivins' RMR-1029 anthrax preparation, but asserts all were "ruled out" as lone perpetrators. FBI never tried to rule any out as part of a conspiracy, however.
There is also a tidbit at the end of the story that hints that the FBI's investigation into foreign sources was not quite up to snuff.