The great majority of child molesters are not "sick", they are criminal.  If they won't do it while a cop is watching them, then their behavior is neither compulsive, nor uncontrollable.  They rationally evaluate their chances of getting caught and punished.  This is why the vast majority of offenses are done by a family member, or a close friend.  They are counting on that relationship, to not being reported to the police.  They correctly estimate that usually, the worse that will happen, is that they get banned from unsupervised contact with the extended family's minors.  Many do end up in court, and are usually punished proportionally to the actual trauma they may have inflicted upon the victim(s).  Treatment for them is usually a matter of disabusing them of their notions that what they did was relatively harmless, with a modest term of supervision.  The violent rapists/killers, of either child or adult, are in a whole different class of offender.  No empathy towards others, evil!