What should I do about a offender?

Depending on the State Offenders must be register with local law enforcement to keep thier locations up to date. If they are not up to date its a violation of thier probhatioin or parole. Reporting to local law enforcement you may get mixed result bigger municipalties may have special units that would act on a offender that failed to register his/her updated address. I found 1 offender right across the street and he looked like a "harmless" old man. His registration was outdated, though I moved a few months later. Hope it helps.