By a 5-4 vote Monday, the court says the Constitution requires that young people serving life sentences must at least be considered for release.
The court ruled in the case of Terrance Graham, who was implicated in armed robberies when he was 16 and 17. Graham, now 22, is in prison in Florida, which holds more than 70 percent of juvenile defendants locked up for life for crimes other than homicide.
"The state has denied him any chance to later demonstrate that he is fit to rejoin society based solely on a nonhomicide crime that he committed while he was a child in the eyes of the law," Justice Anthony Kennedy wrote in his majority opinion. "This the Eighth Amendment does not permit."
Chief Justice John Roberts agreed with Kennedy and the court's four liberal justices about Graham. But Roberts did not join the majority opinion as it applies to all young offenders who are locked up for crimes other than murder.
Life sentences with no chance of parole are rare and harsh for juveniles tried as adults and convicted of crimes less serious than killing, although roughly three dozen states allow for the possibility of such prison terms. Just over 100 prison inmates in the United States are serving those terms, according to data compiled by opponents of the sentences.