http://www.usatoday.com/news/washington/2008-08-18-FBI-anthrax_N.htm?csp=34
USAToday dissents from the “one flask” view:
“•The markers led the scientists to two flasks cultured by Ivins.”
New York Times has the most circumspect article, twice noting the “100 scientists” angle.
http://www.nytimes.com/2008/08/19/us/19anthrax.html
F.B.I. Presents Anthrax Details but Says It Can’t Erase Doubts
By ERIC LICHTBLAU and NICHOLAS WADE
Published: August 18, 2008
...At a two-hour briefing for reporters, Dr. Majidi was joined by seven other leading scientists from inside and outside the bureau. They discussed in intricate detail the halting scientific path that led them from two main samples of anthrax used in the 2001 attacks, to four genetic mutations unique to the samples, to 100 scientists in the United States who had access to that particular strain, and ultimately to Dr. Ivins...
The unusual presentation by the bureau on Monday was intended to quell those doubts, but some scientists remained skeptical. They said it would be months before they were able to evaluate fully the strength of the forensic evidence, and the new process used, in an independent setting...
But they said they believed that the anthrax was naturally fine enough to seep through the envelopes used in the attacks and that mail sorting equipment dispersed it into the air at several postal processing facilities. Two postal workers in Washington, D.C., were among those killed.
Investigators said a number of circumstantial factors, like Dr. Ivins’s unusual nighttime hours at his laboratory in the days before the anthrax letters were mailed, pointed to him as the killer. But the case relied largely on the scientific evidence that officials said had led them back to two one-liter flasks in his lab....
They also countered a principal scientific criticism of the investigation: that the spores had been weaponized with a special coating and therefore could not have been made by Dr. Ivins because he did not have the necessary equipment. This criticism is based on the presence of silica in the anthrax-laced attack letters. However, the F.B.I. scientists said that the silica had been imported naturally by the anthrax spores from their environment and that there was no evidence of weaponization...
...Eventually, 8 of the 1,000 strains were found to carry the four mutations, and 100 scientists had access to, or were associated with, the strains. All of these scientists were investigated. The “body of evidence,” officials said, pointed to Dr. Ivins...
The F.B.I. scientists said they had been able to reverse-engineer the production and properties of the attack spores, producing bacteria that flew into the air with ease. One person could have prepared the attack anthrax in three to seven days, with equipment available at Fort Detrick, a bureau expert said.
The F.B.I. had been unable to reproduce one feature of the attack spores — their high level of silica — but attributed that to natural variability.
Dr. Spertzel said the failure to reproduce the silica content “raises more questions.” But he added that if the F.B.I. was right and “an individual can make that kind of product, just by drying it, we are in deep trouble as a nation and a world.”....
At a two-hour briefing for reporters, Dr. Majidi was joined by seven other leading scientists from inside and outside the bureau. They discussed in intricate detail the halting scientific path that led them from two main samples of anthrax used in the 2001 attacks, to four genetic mutations unique to the samples, to 100 scientists in the United States who had access to that particular strain, and ultimately to Dr. Ivins.