Clint had said HIMSELF that he was told Hailey is dead
No agency believes he has her hidden as he was publicy cleared by LE of being involved in his daughters disasppearance unlike her mother.
The only person to specifically have "cleared" him was the sheriff many months later after doing a polygraph.
The problem is that early on in the case CD was on TV bragging that he was willing to take a polygraph test, but that no one asked him to. Then, much later, the sheriff makes a public statement that he was just been given one and "passed", hence wasn't a suspect. This is very unusual because generally LE don't comment about who is given a poly or if they passed or not. They certainly don't do press releases about it.
Just how the sheriff reached this conclusion is not clear, since know one has any idea what happened to HD, so it is impossible to "clear" anyone. Certainly, there is evidence from multiple angles suggesting that HD went to CD's house that day, plus, according to the grandmothers account of that day CD would have been alone at home when HD dissappeared, allegedly on the way to his house. That doesn't mean that CD had anything to do with what happened, but it also means that he can't be eliminated. So how could the sheriff conclude that he was?
We also have early on in the case the Sheriff making claims about child *advertiser censored*/bestiality being found at HD's residence, and pursuing SA on that basis, even though this later turned out to be false.
IMO the sheriff early on decided that the guilty party was SA and subsequently developed tunnel vision in the investigation focussed on that theory. That would explain why they had largely ignored what was going on in CD's side of the divide and why they didn't give him a poly.
Then, later on the sheriff would have come under pressure from other agencies, such as the Texas Rangers and the FBI, asking why the investigation was not exploring other alternatives. In response to that, months later, he about-faced and tested CD, then pronounced him cleared. In that scenario the sheriff would have been acting petulantly to internal criticism from his peers, not necessarily because he had a real basis for his conclusion.
As for HD being dead, the only person to have suggested that IIRC was the former city manager of CC, and he promptly about faced on that when challenged. I doubt that any LE would seriously have told CD that HD was dead without compelling evidence for that, and as far as we know there is none. It is just not the sort of thing any responsible LE would do. So, if CD is saying that now, he is either making it up, or he is extrapolating from what Kaempfer originally claimed.