and it ends up costing you. deadly fruit. fresh summer cantaloupe. it seemed healthy. but it caused one of the deadliest food outbreaks in u.s. history. any one of those things would have been prevented, this tragedy probably wouldn t have occurred. how it could have been prevented and could still happen again. revealing investigations. fascinating characters. stories with impact. this is cnn presents with tonight s host, randi kaye. it is one of the worst atrocities to emerge from the war in afghanistan. in a chilling shooting rampage, sergeant robert bales allegedly shot down 17 civilians. his lawyer says he may have had post-traumatic stress disorder. a diagnosis that could be used in his defense. that is a scene playing out more and more in courtrooms around the country. vets charged with violent crimes are saying ptsd made them do it. and juries are having to decide, should ptsd be a defense for murder? chris lawrence investigates. reporter: raymond william