(CBS) In the nearly 20 years since Judge Richard Barton sentenced then-17-year-old Joseph Donovan to life in prison without the possibility of parole he has presided over countless murder trials, but Donovan's sticks out.
"I remember it well," says Barton. "Looking back, it was an unfair punishment."
Barton is not alone in his assessment of Donovan's sentence. On Sept. 19, 1992, Donovan and two other Cambridge teens were walking on the campus of the Massachusetts Institute of Technology when they came across a group of students. One of the students, a Norwegian exchange student named Yngve Raustein, apparently said something that irked the boys - though Donovan can't even remember why - and Donovan punched the man.
Then things got really ugly.
As Donovan nursed his injured hand, 15-year-old Shon McHugh pulled out a knife and stabbed Raustein to death. The teens ran and were later caught, arrested, and all charged with first-degree felony murder. Because of his age, 17, Donovan was tried as an adult, while McHugh was tried as a juvenile. Donovan was convicted and because of Massachusetts' sentencing laws, was given a mandatory sentence of life in prison without parole. McHugh got just 20 years - and was out in 10.
Donovan, now 37, is still in prison.
"When you're sentenced to a natural life sentence you're considered to be a throw-away person," says Donovan.
Crimesider visited Donovan in the Shirley Medium Correctional Facility in Shirley, Mass., where he talked about the recent that found mandatory sentences of life without parole unconstitutional for defendants under 18 years of age. In light of this ruling, Donovan's pro bono attorney, Ingrid Martin, is working on a brief petitioning the state of Massachusetts to revisit his sentence. It is now possible that a judge could find Donovan has served enough time for his part in Raustein's death - but there are challenges.
"The Supreme Court is catching up with modern understanding about juvenile culpability and their ability to be reformed," says attorney Martin.
The decision, handed down in June and written by Justice Elena Kagan, concluded that "mandatory life without parole for a juvenile precludes consideration of his chronological age and its hallmark features - among them, immaturity, impetuosity, and failure to appreciate risks and consequences."
But, says Martin, there isn't yet a clear precedent for how the decision will affect those already serving life under sentences now deemed unconstitutional.
And Donovan isn't the only one wading into the new area of the law. According to the Pittsburgh Post-Gazette, the Pennsylvania Supreme Court heard arguments on Sept. 12 about how to handle the state's estimated 470 inmates who were sentenced to life without parole for crimes committed before they were 18.
While Donovan and his family say they are trying to keep their hopes for his possible release under wraps, they all have fantasies about making up for lost time.
"All he's known for the 20 years are those four walls," says Donovan's mother, Mary Morgan, who imagines cooking spaghetti and meatballs for her son on his first day out. "It would be nice for him to see the world. I'd like to take him to the ocean."
Morgan and Joe's father, Joseph Donovan, Sr., divorced years before Joe was convicted, but have remained close in support of their son.
"It'd be nice to be his parent again," says Donovan, Sr. "And I'd like to know the joy of being a grandfather."
Donovan, who has discovered a talent for drawing while incarcerated, would love to attend art school, and talks timidly about the possibility of "finding somebody" and "settling down." Like his mother and father, he is an animal lover, and says one of the first things he would do if he gets out is get a pet.
Inside prison, Donovan has educated himself, and he is thoughtful and articulate when speaking about the system that tried and sentenced him as an adult, as well as the barriers to freedom he still faces. In 2010 - before the new Supreme Court decision - his request for a commutation hearing was denied.
"It's kind of disheartening," he says. "It's really going to be up to a judge to look at my case."
And in some ways, that's all he's ever wanted. Despite his reservations about the justness of the sentence, Judge Barton says she had no choice but to impose the mandatory punishment. A mandatory punishment that, in the wake of the June Supreme Court decision, no American juvenile will face again.
Video produced by Julia Dahl and filmed and edited by Edecio Martinez