Damn, that is hard stuff man.
But perhaps you can still tip off the authorities with an anonymous tip or something like that?
If they had been aware of this guy, it might be enough to re-investigate or something. If they were not, it might put them onto him.
Surely it can't hurt to still report the guy?
Personally I dont know what I would have done in that situation. Nobody can say that for certain untill it happens, and then you just act, for better or for worse.
If I had figured out what was happening I'd probably be boiling with rage, or scared out of my mind, or both. At any rate the end-result probably wouldnt be pretty.
The thought that such people exist and the possibility that they might harm a child makes me so incredibly mad. It's cases like those that make me wish we had a death penalty in Holland, because that kind of person doesnt deserve to live.
They thrive on the suffering of others, and nothing good comes of their life.