There's been a recent development in the Lisa Irwin case, in which a PI has been hired (it's not known whether it was by the family or the media). It reminded me a lot of the the Ramsey case where the parents also hired PI's. However, one big difference is that the PI in the Irwin case comes across as some full of BS publicity hound. If this guy goes on a TV show and starts giving some ridiculous story about happened to Lisa, with "Private Investigator for the Irwins" under his name, it will destroy their relationship with the public. The Ramseys hired investigators too, but they knew how to market them correctly. With Lou Smit, we constantly heard about how he had solved 200+ crimes. With Bill Stanton, the Irwin's PI, we hear about how he used to work at a nightclub and that he wants to be a celebrity.
I think the Lisa Irwin case is going to play out like the Ramsey case should have if the Ramseys didn't have money. Whenever Bill Stanton goes on a TV show, the media will inform the public that he is a "PI hired by the family" and then Bill will makes some crazy claim like Lisa was abducted by aliens. In the Ramsey case, when ever one of the investigators appeared on a TV show, it's never mentioned that he was hired by the family, instead they'll talk about how he has decades of experiences solving hundreds of cases and that after reviewing the Ramsey case, he came to the conclusion that the Ramseys are innocent.
I think the big difference between how the PI in the Irwin case come across and how the PI's in the Ramsey case came across has a lot to do with the Ramseys having the money to hire a PR firm. There was no way they were going to put someone like Bill Stanton, front and center, to speak for them. If the Irwins are innocent, I can see why they would be open to using someone like Bill who is probably claiming that he'll find their daughter and keep her case in the spotlight for free (possibly being paid by the media). But the Ramseys had money, so whether they are innocent or not, there's no way they would agree to have some nut speak for them because they had the means to hire someone with credibility, whether the goal was to find the killer or to create a public defense for the family.