Whoever did this should be castrated and left in prison.
With that said I don't know too many 3 year olds that can speak any language well enough to explain what happened especially in a situation like this. I just hope this guy isn't being convicted before proof it was him. There would be DNA left behind that could be matched although that process in thailand has been suspect in the past.
Just because he has visited in the past and brought goods, supplies and candy for children isn't proof nor is visiting a drug party with numerous people drunk and on drugs. I suspect it will be found to be him no matter what.
I think everyone there should be investigated and charged as they supposedly had her in their care, or lack there of.