However it was done, said Majidi, "it would have been easy to make these samples at" Ft. Detrick, Md., home of the Army's infectious diseases research facility.
Over the past several years, the FBI searched worldwide to gather 1,070 samples of deadly Ames-strain anthrax -- the type used in the mailings. Only eight of those anthrax samples contained four distinct genetic mutations -- the same mutations found in the mailings. And each of those eight samples, officials allege, could be traced to parent material known as RMR 1029 that was maintained by Ivins in a one-liter flask he controlled in a Ft. Detrick lab.
In addition to the far-reaching scientific efforts, investigators used conventional police work to exclude as suspects about 100 others who may have had access to RMR 1029 at Ft. Detrick and elsewhere.
In his view, Majidi said, the government amassed "a body of powerful evidence that allows us to conclude that we have identified the origin and the perpetrator of the 2001 [anthrax] mailings."
Starting in 1980, Ivins worked as a microbiologist at the Army's Medical Research Institute for Infectious Diseases, or USAMRIID, at Ft. Detrick. Both before and after the anthrax mailings in September and October of 2001, which killed five people and set off a wave of fear on the heels of the Sept. 11 terrorist attacks, he prepared spores used in experiments on animals in an effort to develop or improve vaccines against anthrax.
The parent material for the anthrax mailings -- the one flask of RMR 1029 -- was derived from a mixture of various batches of spores, originally totaling 164 liters, said Chris Hassell, a chemist who since June has headed the FBI's laboratory. Hassell said that Ivins produced RMR 1029 from spores shipped from 22 "production runs" at Ft. Detrick and from 13 runs received there from the government's Dugway Proving Ground in Utah.
When the FBI sought scientific help in analyzing powder recovered from the mailings, it turned to USAMRIID -- and to Ivins. Officials who addressed the media Monday acknowledged for the first time that Ivins had helped the FBI compose the "protocol" for early subpoenas that sought anthrax samples from USAMRIID scientists, including Ivins.
In February 2002, even before his subpoena arrived, Ivins submitted a sample that violated the protocol, the officials said. And because FBI officials concluded that the protocol violation would make Ivins' sample inadmissible in court, the bureau destroyed it. In April 2002, Ivins gave the FBI a second sample, which did not match the RMR 1029 parent strain.
