I read this interview about a week ago on CNN. The speaker was ex-Delta Force. He had a lot of theories on the sniper, and from what I've read so far, he's been right on about everything. He guessed that they were firing out of a bored hole in the back of the van - he guessed that they were making all right-hand turns to exit quickly - he guessed the father-son thing - he was so right on, it's amazing.