All sex offenders receive mandatory treatment, and prison terms for their criminal offences. Not all states require mandatory treatment of sex offenders in prison. Child molesters are shady looking individuals who I wouldn't allow to have access to my child. If we had the abilty to tell who they were by their job, and or their looks children would be much safer. However, we don't.
Education is the key.
Make sure your child knows that they can come tell you if someone harms them. Make sure they know it is never their fault. Make sure they know, most importantly, that you will believe them.