Just because his house and car were searched does not mean LE did not believe his alibi. We are looking for a missing person here. You do not take a person's word for anything in an investigation like this. Of course LE is going to do these things and ask him to take a polygraph. That does not mean LE "debunked" his alibi, it means they did not simply take his word for it, and they were doing their job thoroughly.
If LE simply said, "Okay, JW, we believe you!" and did nothing else, can you imagine how many people would be in outrage?
The whole suspecting X and Y simply because they retained a lawyer is getting old. Time and time again it has been said that innocent people need representation too. You can not convict a person because they wanted protection. Yet people insist on finding a person suspect because they hired a lawyer. I find it derailing. JMO - I am not telling people not to speculate about it, I am just letting them know my feelings about this type of speculation.