These numbers generally come from prison statistics, and are applicable to only thise that have been charged, found guilty, and served a prison sentence. If they are reincarcerated for any reason a second time, the number is fed into the system, so that these statistics are often artificially inflated.
I use professional, peer reviewed studies, in combination with forensic psychology studies done in prisons, and those offenders who were never jailed but part of a treatment study. It is a much wider data base and provides more accurate numbers that are realistic and pertain to all offenders and not just those that have been jailed. When we talk about re-offending, we aren't talking about criminal reoffending necessarily.
