Poor man.
The police lured him into attempting to seduce a 15 year old girl, who didn't exist.
Kind of hard to say a crime was committed when there was no victim.
Yes I do realise that if there was a real girl involved his actions would very wrong, and even worse if he actually managed to take advantage of her, but I really don't see this as a case of the police taking an active predator off the streets. I think a more suitable sentence would be counselling, rather than putting him in an environment with other criminals.
And the police could try solving actual crimes that have been comitted, rather than trying to create new crimes and new criminals.