The rundown on the Mccann case:
>The police dog sniffed a corpse on the clothes of the father, in Madeleines bed and the trunk of of their car
>The parents claimed they were at some bar down the street but repeatedly checking on their children. The barkeeper or waitress said they didnt leave at all
>The chief investigator got removed from the case and iirc fired for wanting to investigate against the parents despite parents and family always being the initial prime suspects
>The mother was some doctor in charge of anesthesia and changed the profession shortly after. One cop told how despite all the the noise and haste going on in the appartment during the investigation, their other child simply slept through.
>The parents got involved with Sir Clement Freud (who was exposed for being a pedo after his death) and Sir Phillip Green (very likely a pedo himself too. In general the knighting seems to be some honorary thing for pedos)

My guess is they whored out their daughter to some elites. Either to get inside the club, for money, or to delete some other nasty records of them. They gave their children some drug to keep them sleeping and then left them alone with the pedo. The anesthesia however killed McCann, and they hastily faked some kidnapping with involvement of the elite friends they tried to get on their side.