Former New Jersey attorney general John Farmer served as senior counsel to the 9/11 Commission, tasked with investigating the government response to the attacks. His new book, The Ground Truth, picks up where the commission left off " taking a deeper look at the government's ... response to the attacks and exposing officials determined to hide their failings from the inquiry. Farmer uses newly released transcripts and recordings to cast doubt on the official version of events. He spoke with TIME. [Time:] Why do you think officials tried to obscure [the truth about 9/11]? [Farmer:] It's almost a culture of concealment. You have someone like Sandy Berger ... taking rather extreme measures to remove documents from the National Archives and hide them at a construction site where he could retrieve them later and destroy them. There were interviews made at the FAA's New York center the night of 9/11 and those tapes were destroyed. The CIA tapes of the interrogations were destroyed. The story of 9/11 itself, to put it mildly, was distorted and was completely different from the way things happened. If what the government is telling you isn't true, then the truth could be anything. I think there is evidence that the truth wasn't told and that at least some of that was deliberate.