If someone kidnapped the girls as a revenge thing, what would they do with them? It would not be easy to keep and maintain two girls all this time. I know drug people are not famous for thinking ahead, but if they were trying to send a message or whatever, I guess it has not worked, since apparently LE has not figured out where they are.
I know this has happened a few times but not often, and not with the children missing for this amount of time...if that were the case, it seems the parents would know right away who would have taken them by now. LE would have tracked them down. It is not that easy to hide out anymore (as a rule.)
I wish this was what happened, but it seems more like an intentional kidnapping by a sex predator, and probably a local one who had seen the girls before. Probably not even an RSO, rather someone no one knows is a sex predator yet.