but as time has worn on and his daughter of course has not been found, any new lead becomes really important to him. he guards his emotions against it but you can sense it that he feels strongly on this and he wants it looked at. >> the prosecutors, though seem skeptical about this man and his tip. i wonder why? >> reporter: they are. they don't share, of course everything they know to us despite the questions we ask. they primarily point out that information that they received from marriott that said the construction or what he described as construction didn't exist at that time. we've already seen that there are some who refute that. they just don't buy it. they have looked at the case file. this is a new prosecutor. he's gone through thousands of pages and he says it doesn't add up. still, it's a lead. i don't see why he has to have proof positive to go forward. but it seems he does. >> well it's a great question for tom fuentes, right? you were at the fbi, sort of