I think you are on dangerous ground here , due to your devious behaviour on Facebook.
What exactly are you trying to achieve?
If you have genuine concerns about this person and his attitude to young girls, and you can substantiate these concerns with real. hard evidence , then you must inform the police and let them deal with it.
It is not enough for you to believe he has a certain attitude.
Does this person merit the possibility of having his life ruined, by your very devious amateur detective work based on a deception by you on the internet.?