The McCann Rule-of-Thumb is raise money, exert pressure, and remote control an investigation from abroad by having your superior country’s resources criticize every aspect of the investigation.
Make sure the case stays in the media because that will focus local cops on searching and investigation. [No, it will focus them on reading the tabloids criticizing what they’re doing].
The McCanns Rule-of-Thumb also suggests waiting as long as possible to give statements to the police, and telling the police to follow the leads you give them. In short, control the narrative. Also, make sure siblings don’t talk to the investigators, as this might actually get it on the right track.
The McCann-Rule-of-Thumb requires setting up PR spokesmen, and not dealing with the police but communicating instead to the public, especially through spokesmen, book deals, documentaries etc. All the profits from this naturally go to the search for the missing child, until it turns out it’s mostly used to pay for PR, legal fees and occasionally, an expensive mortgage.