My read of this from Johnny's post and what he has said in the other thread where this is being discussed is that the guy has just told Johnny these things - Johnny doesn't have any further information.
So what has happened is this: A (former) friend has told Johnny that he was abused by his father and that he has acted out by abusing children himself. He has also let Johnny know that he will abuse his own children if he has any, but what he means by that isn't clear: does it mean he is that callous and evil, or does it mean he is that overwhelmed with guilt? Either way it all looks very dangerous.
I know if someone were to come here and say such things in chat or on the DB, MS regards this as reportable to the authorities. What does MS do? Which authorities?
If one of the mods answers this, Johnny, I would say do the same and then stay away from the guy.
I understand the sentiment behind admonitions that you should act vigorously and decisively, and I too would like to see this guy pay a heavy price. But exactly what is in your power to do, apart from reporting to the police (or whoever MS reports to)? Pressing the matter further could lead you into big legal trouble (libel?), personal danger, and risk to your own recovery.
We leave murderers to the police to chase, and if we do that it doesn't mean we are uncommitted to a society free from killing; it means we are recognizing whose job it is to deal with these things. It seems to me that this is another one for those professionally qualified, and that a survivor can only report what he knows, to those who need to know it.
Take care,
Larry