I hate to seem like I am harping on the search warrants, but bear with me. A classmate of mine went missing in 1996, and her family and friends knew for a fact the last person she saw was her BF, he admitted he was the last one to see her, he had motive to make her disappear, and she has never been found. Yet even with credible information the police were denied a search warrant, and never even took the guy in for questioning! She remains missing. I always think if they would have just granted a search warrant, she might not still be missing. Her case is on this site, and I can provide a link if it's allowed.
In this case, they got a search warrant for a place they didn't really need one, and didn't get one for a place they really should have. It would be really horrible if 20 years were to pass and one little "should have" could have made a difference.