I saw Vincent Bugliosi speak at The Commonwealth Club in San Francisco this week. He was in town to talk about his new book that claims Lee Harvey Oswald acted alone in the assassination of John F. Kennedy.

For the last eight years, Bugliosi has worked on the book, entitled "Reclaiming History: The Assassination of President John F. Kennedy." 

In his book, Bugliosi laughs at all of the conspiracy theories associated with the JFK assassination. "Pure moonshine," he calls them.

Mr. Bugliosi, 72, the former Los Angeles County deputy district attorney who won a conviction of Charles Manson in 1970 and then wrote the best seller "Helter Skelter," says he's written the definitive account of Dallas' darkest day.

Over the span of more than 1,600 pages, he works with a prosecutor's skill to disassemble every conceivable theory and has allegedly proved beyond a reasonable doubt that Lee Harvey Oswald alone killed the president.

But many of us, including myself, aren't convinced. The most recent Gallup Poll, taken in 2003 on the 40th anniversary of the president's death, found that 75 percent of Americans believe in a conspiracy. Only 19 percent believe the Warren Commission, which, in my opinion, was a kangaroo court of the highest magnitude. Is the public completely deluded or is there something to this conspiracy thing?

Mr. Bugliosi says his book "settles all questions about the assassination once and for all."

"No reasonable, rational person , and let's italicize those words, can possibly read this book and not be satisfied beyond all reasonable doubt that Oswald killed Kennedy and acted alone,  Bugliosi writes.  So, the vast majority of reasonable conspiracy theorists are going to be swayed by this book. But those on the jagged margins of the conspiracy community are allergic to the truth, and they will not agree with this book."

I think Bugliosi must not be thinking clearly. For him to completely discount all of the conspiracy theories just isn't logical. There is more proof now than ever before that someone fired shots from the grassy knoll; that Oswald was a patsy; that Ruby had mob connections; that the autopsy was tampered with and that more than one type of bullet was fired at JFK.

Bugliosi reminds me of someone who gets rolling in one direction and works so hard to come up with a particular conclusion that he becomes blind to all of the other credible evidence that exists.

As forensics become more sophisticated and people delve even more deeply into this mystery, I truly believe that we'll eventually know who killed John F. Kennedy on that tragic day in Dallas. And we'll be able to use Bugliosi's book for something useful - like a big paperweight or a door jam.