I'm not sure what you mean.
The usual procedure is to inform the Police then once the Police have been informed, a letter is sent out to parents to inform them that an incident has occurred and that the matter is at hand.
This is mainly done to contain hysteria and prevent it before it happens.
Kids talk. Little Miss 3 could come home and say "Mummy, Katie told me that Dylan licked her on the woo woo..." and the parent would be like, what? And ring her friend, another parent at the centre and it would get out and get nasty. I've seen that happen.
By dealing with it formally and as per the legislated procedure, parents are rightly informed that a safety breach has occurred, the circumstances surrounding this (although not in depth) and that the matter is being dealt with.
Only the other day I received notification by way of letter from the centre my child attends regarding an incident where Police had to be called. I didn't fret. I simply noted it and followed it up. Easy.
Hiding it behind closed doors doesn't do anyone any favours.
You can still maintain a level of confidentiality and still keep people informed.