You son't seemed to have quite grasped the situation dave.
The type of crime is unknown.
Until the nature of a crime is established, you don't rule out potential suspects.
But you do rule out people who you are completely satisfied (after examining all the evidence regarding the nature of all possible crimes) do not qualify as potential suspects for any of them. This is what SY have done in relation to the McCanns and their friends. SY have the evidence/ information and the means of establishing facts that we cannot possibly establish - as we are only in possession of
some of the necessary info required to do that. And even the info we do have (files) cannot be relied on to be accurate.
SY police officers are the experts and have all the info. We are amateurs and have only some of the info. Therefore it's no contest IMO. I'll stick with the experts. My personal opinion of the McCanns as parents doesn't come into it. Unfortunately Stephen IMO -
your opinion of the McCanns rules everything.
(oops sorry I think I'm off topic -so won't post here again on this subject)