NEW : Ivins lawyers say documents , statements are n't `` concrete evidence '' Federal prosecutor says Ivins acted alone in attacks that killed hundreds . Records say Bruce Ivins ' tried to mislead feds with false samples of bacteria . His case has fueled skepticism about the allegations against Ivins , and experts in the field have disputed some details that have emerged from the investigation . FBI releases five of pages to public .
NEW : Ivins lawyers say documents , statements are n't `` concrete evidence '' Federal prosecutor says Ivins acted alone in attacks that killed hundreds . Records say Bruce Ivins ' tried to mislead feds with false samples of bacteria . FBI releases five of pages to public .