Though DOJ will presumably insist that Ivins did it.

The FBI is expected to issue a final report today on its six-year investigation of the 2001 anthrax letter attacks, according to the attorney representing former Frederick resident Bruce Ivins, a Fort Detrick scientist accused of planning and carrying out the attacks that killed five people and sickened 17.
“The U.S. Attorney called me and said they would close the case today,” said Rockville attorney Paul Kemp.
The report will close an investigation in which Ivins, a senior researcher at the U.S. Army Medical Research Institute of Infectious Diseases, was eventually identified as the only person suspected of mailing the deadly letters to the offices of U.S. senators and media companies.
Well, I guess this eliminates one of the excuses Robert Mueller has used to avoid an inquiry into FBI’s conduct during this investigation.