WASHINGTON — A Northern California man who was sentenced to life in prison without parole after being convicted of felony murder committed when he was 17 might gain his freedom eventually, under a brief Supreme Court ruling Monday that's the latest indication of potential leniency for similar inmates.

For 23-year-old Bradley Blackwell, who’s in a state prison in California’s San Joaquin Valley, the one-paragraph decision Monday means another chance to challenge his dead-end sentence. For hundreds if not thousands of other inmates nationwide, the decision underscores how a court ruling rendered in 2012 will ripple outward for years to come.

“I’m very encouraged,” Blackwell’s attorney Donald Thomas Bergerson said in a telephone interview Monday. “This is a very humane kind of ruling.”

The Supreme Court’s decision, issued without elaboration, doesn’t guarantee Blackwell a more lenient sentence but it directs a California appellate court to reconsider his sentence in light of the high court’s 2012 decision involving juveniles.

Nationwide, more than 2,500 people are serving life without parole for murders committed when they were under 18.

In a 5-4 ruling last June, the Supreme Court struck down mandatory life sentences without parole for crimes committed by juveniles. Over the objections of court conservatives, the narrow majority concluded that juvenile offenders require special consideration.

“In imposing a state’s harshest penalties, a sentencer misses too much if he treats every child as an adult,” Justice Elena Kagan wrote for the majority. “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.”

The 2012 decision most immediately affected two inmates from Alabama and Arkansas who’d brought separate but related appeals. More broadly, it affected others who are serving similar sentences.

Last month, for instance, a Texas appellate court, acting at the behest of the Supreme Court, reconsidered the life-without-parole sentence of convicted killer Herbert Ray Wilson. Wilson was 17 at the time of the 2007 murder, in which a pregnant Houston woman was killed during an apartment burglary. The appellate judges, guided by the Supreme Court’s 2012 sentencing decision, ordered a trial court on Dec. 13 to redo the punishment stage of Wilson’s trial.

The reconsideration of strict juvenile sentences also reflects a longer-term trend.

In a 2005 case from Missouri, the Supreme Court ruled that it was unconstitutional to sentence someone to death for a crime committed while younger than 18. In 2010, the court ruled in a Florida case that a juvenile couldn’t be sentenced to life without parole for a crime that didn’t involve murder and the possibility of a death sentence. Then last year came the decision striking down mandatory life-without-parole sentences for juveniles.

“This is just the next step in an evolving doctrine of jurisprudence,” Bergerson said Monday.

There’s a wrinkle, though, in Blackwell’s case, as well as several others that the Supreme Court has sent back recently for a second look at sentencing. Unlike the juveniles in last year’s Supreme Court case, Blackwell wasn’t facing a mandatory life-without-parole sentence. The trial court had the option of imposing a lesser sentence, but it chose not to.

“After considering, among other things, (Blackwell’s) age, his extensive criminal record and the heinous nature of the murder, the sentencing court concluded that ‘even at his young age’ (Blackwell) ‘should not be granted the possibility of parole,’ ” Seth K. Schalit, supervising California deputy attorney general, wrote in a brief filed on behalf of California.

Schalit further noted that a 2012 California law allows state inmates to petition for leniency if they’re serving life without parole for crimes committed while under 18. Part of the new law requires inmates to describe their “remorse and work towards rehabilitation.”

The crime for which Blackwell is incarcerated at Kern Valley State Prison occurred in Sonoma County, north of San Francisco. Though he wasn’t convicted of being the triggerman, Blackwell was part of a two-man team that apparently sought in February 2007 to rob a Petaluma resident of money and crystal methamphetamine. Instead, the Petaluma man died after being shot five times. Blackwell’s partner, Keith Kellum, pleaded guilty to second-degree murder.

Kellum was 22 at the time of the murder. He’s serving a term of 15 years to life at Pleasant Valley State Prison, also in California’s southern San Joaquin Valley.

“We are on very perilous grounds in punishing young people if we don’t recognize they have frailties and vulnerabilities,” Bergerson said.