" ... New details of the investigation, revealed in recent interviews, raised questions about when the bureau focused on Ivins as the likely perpetrator and how solid its evidence was. In April 2007, after the mailed anthrax was genetically linked to Ivins's laboratory and after he was questioned about late-night work in the laboratory before the letters were mailed, prosecutors sent Ivins a formal letter saying he was "not a target" of the investigation. And only a week before Ivins died did agents first take a mouth swab to collect a DNA sample, officials said. ... "
STORY