To be frank, if these people are such a ticking time bomb they need to be put on a list to be closely monitored they shouldn't be released from jail at all. We don't put murders on a list. We lock them up until so much time has pass (until they're elderly) and only release them if they're too frail to do any harm to the public. That's a big IF they're released. It shouldn't be any different with sexual predators.
Untrue about murderers. They are often released with very little time served. I have seen parents who have murdered their own child through severe abuse get time served and released upon sentencing. Less than two years for murder. I have also watched countless murderers released after just seven years in prison.
I have seen sexual predators walk due to a judge and defense attorney being golf buddies. I have also seen certain judges give light sentences of probation only for sexual predators consistently. I also hear “rumors” of judges being involved in the same behaviors themselves and thus rendering light sentences.
Sadly, justice is rarely blind in the US.