Juvenile Law Question...

In order for me to ask the question properly, I'll have to explain some background information. My boyfriend is now 23 years old. He grew up in a less than "ideal" household. Himself and two sisters were sexually abused by their parents, uncle and grandfather. He was in and out of child protective custody for most of his childhood. When he was 14 years old, he sexually assaulted a 6 year old child. They housed him in a unit until he was 16 years old and stood trial. The judge sentenced him to 15 years (I believe this sentence was beyond excessive). He has now served 7 years of his sentence and we are trying to start our lives together. Of course he is a registered sex offender so things are difficult to say the least. We were wondering if there is anything we can do about maybe "getting time served" because he WAS only 14 years old...or maybe there is some other way to go about cleaning up his record a little bit. His counselors all agree that he is not a threat to society, he was a young boy confused, considering the action he witnessed every day at home. If anyone could please point us in the right direction, I would greatly appreciate it.