I heard the author on a radio talk show.
This first bullet missed, but they found a dent or something in Dealey Plaza that indicated its existence.
Do a google search on third bullet newsweek and you get the link, but it must be behind a firewall, because it doesn't come up for me.
(I was surprised there still was a Newsweek!)
Thanks, that was a great read, and I just posted it at
http://www.freerepublic.com/focus/f-news/3230060/posts