http://www.mcclatchydc.com/2011/04/20/112520/was-fbi-too-quick-to-judge-anthrax.htmlScouring the anthrax-laced mail that took five lives and terrorized the East Coast in 2001, laboratory scientists discovered a unique contaminant — a tiny scientific fingerprint that they hoped would help unmask the killer.
One senior FBI official wrote in March 2007, in a recently declassified memo, that the potential clue "may be the most resolving signature found in the evidence to date."
Yet once FBI agents concluded that the likely culprit was Bruce Ivins — a mentally troubled, but widely regarded Army microbiologist — they stopped looking for the contaminant, after testing only a few work spaces of the scores of researchers using the anthrax strain found in the letters. They quit searching, despite finding no traces of the substance in hundreds of environmental samples from Ivins' lab, office, car and home.