...Here in Colorado we have what is called "mandatory parole" - which is probably not what you think it is. It does not mean that it is mandatory to release you early, it means that even if you are released after serving your entire sentence, you will be considered "on parole" and will have a parole officer assigned and live under the threat of being sent back to prison (even if you already served your entire sentence). Hence, you could do almost 15 years on a 10 year sentence because if you are released after doing the 10, you will still have to do 5 years of "parole" and could be sent back if you violate any of the terms of parole. In fact, nearly 40% of the intake into Colorado prisons is from "technical" parole violations, which are violations of parole conditions that are not felony crimes. This system has created a terrible sense of hopelessness among those caught up in it. My assessment (admittedly based on anecdotal data) is that Colorado parole officers think it is their duty to try and find reasons to violate a parolee and get them sent back to prison. They seem to go out of their way to make success difficult for a parolee, rather than just expect compliance with the law.
[1] http://www.quora.com/Prisons-and-Prison-Life/What-is-it-like...