Nadler was told the Leahy letter contained 1.4% silicon (felt to be "naturally" present), and the Post letter was unable to be tested accurately. But in fact, the FBI got a result of over 10% silicon in the Post letter:
A senior member of the House of Representatives is pressing the FBI to explain why he apparently was sent "incomplete and misleading" information that concealed a lab test showing a soaring level of silicon in one of the anthrax-laden letters that killed five people in 2001.
Democratic Rep. Jerrold Nadler of New York, a senior Democrat on the House Judiciary Committee, demanded an explanation in a letter Wednesday to FBI Director Robert Mueller after a McClatchy story disclosed that the Justice Department gave a sketchy reply to Nadler's 2008 inquiry.
McClatchy also reported in its May 19 story that FBI lab data suggests that a silicon-based chemical may have been added to the anthrax powder to heighten its potency. Some scientists say that concocting such a chemical formula would have been beyond the expertise of the late Bruce Ivins, a longtime Army anthrax researcher whom the FBI blames for the attacks.
Ivins committed suicide in July 2008 after learning that prosecutors planned to accuse him of capital murder. Nadler is among the congressional skeptics of the FBI's decision last year, based solely on circumstantial evidence, to close the investigation and blame Ivins.
In his letter, Nadler noted that a National Academy of Sciences panel that reviewed the FBI's handling of scientific issues declined in February to rule out the possibility that silicon was added to the powder mailed to the New York Post in a failed attempt to enhance its dispersion.
"Were additional samples tested to determine the extent to which the ones examined were representative of the New York Post letter material?" Nadler wrote. An anthrax-laced letter was sent to the newspaper in 2001.
If not, he asked, how would the FBI respond to the academy panel's conclusion? Nadler requested that if additional tests were done, that the results be provided to the FBI and the academy.
At a Judiciary Committee hearing weeks after Ivins' death, Nadler asked Mueller how much silicon was found in the anthrax-filled letters sent to Democratic Sen. Patrick Leahy of Vermont and the New York Post.
Mueller demurred, asking whether he could respond later in writing. Seven months later, the Justice Department replied that the letter to Leahy contained 1.4 percent silicon by mass, but that "a reliable quantitative assessment" of the silicon content in the Post letter wasn't possible because of the "limited quantity of material."
However, a second sample from the Leahy powder contained 1.8 percent silicon, and the bureau advised the academy panel and others that an FBI lab test found 10.8 percent silicon by mass in the Post letter.
Nadler wrote Mueller that the response in April 2009 from M. Faith Burton, an acting chief of the Justice Department's Office of Legislative Affairs "appears to have been incomplete and misleading."
The FBI said the bureau had received the letter and would respond directly to Nadler.Allan Lengel also wrote about this story here, including a transcript of Rep. Nadler's letter.