Another well researched and serious book about 9/11. David Ray Griffin is a Professor of the Philosophy of Religion at Claremont School of Theology. At the beginning of the book he describes how (like most people) he assumed the truth of the "received account" of 9/11 until he started looking at the evidence. When he did look at the evidence in detail, he became so concerned that he wrote this book. He distinguishes very clearly at the beginning between eight different possible understandings of "official complicity", ranging from a cover-up of failure to prevent the attacks to direct involvement in their planning, and he carefully distinguishes the strength of different pieces of evidence and which of the eight views they support.
Buy it from Amazon (UK)