[Ordinary_American]

The Ames strain, which is allegedly the strain used in the mailings, originated from livestock in Texas. It was isolated by American scientists, most notably USAMRIID at Fort Detrick. It was distributed to a number of other laboratories on a rather restricted basis. Samples could have been taken from any of these laboratories and processed elsewhere. So, it is correct to say that we don't know the source of the processed spores contained in the mailings. Use of a strain of American origin, however obtained, would provide the necessary cover for a foreign government or entity trying to keep its involvement secret.

[BlackVeil]

Thank you for the exact details.

[Mitchell]

Use of a strain of American origin, however obtained, would provide the necessary cover for a foreign government or entity trying to keep its involvement secret.

They may simply have picked it for its virulence. After all, if the U.S. government picked Ames over other strains (Vollum, etc.) for the U.S. program, that's quite a recommendation. [Also, isn't the anthrax vaccine less effective against Ames than against some other strains that have been tested?]