Richard O. Spertzel wrote that the anthrax used could not have come from the lab where Ivins worked .
Richard O. Spertzel is a microbiologist who led the United Nations ' biological weapons inspections of Iraq .
Richard O. Spertzel , a microbiologist who led the United Nations ' biological weapons inspections of Iraq , wrote that the anthrax used could not have come from the lab where Ivins worked .