Trust your judgment if countertransference is under control. Sex offenders cannot hide their true self when monitored 24 hours per day for several years. You will eventually realize who is trying to con you and who is committed to treatment (no pun intended). Some con artists eventually take treatment seriously and begin to make a sincere effort. Avoid making quick judgments on any individual. After all, you have several years to make any major decisions.
Finally, you may be surprised by your enjoyment of the work. Most pedophiles can be fairly likable and motivated for treatment, provided you select those with good prognostic features and treat them with respect in a humane, enriched environment. Psychiatric care of the standard hospital patient in modern times is not much different than working on an assembly line. If you are bored with factory work, then developing a sex offender program may reinvigorate your career.
Did I stir up any debate? I hope so!