Washington ( CNN ) -- The Supreme Court struggled Tuesday , speaking in somber tones , when confronting one of its toughest criminal sentencing questions : whether two men convicted of killings committed when they were 14 deserve life in prison without the possibility of parole . The justices seemed to find little agreement on how young is too young in these rare instances , and whether it would be cruel and unusual punishment to forgo the chance that these now-adult inmates may someday be rehabilitated . `` What 's the definition of a child ? '' asked Justice Samuel Alito , trying to draw a constitutionally acceptable line on mandatory sentences for underage murderers . `` It seems to me some of the issues that we have suggested justify a different treatment of juveniles have to do with mental development , '' said Chief Justice John Roberts . `` And those same issues would be taken into account by a jury in considering which of a list of offenses the juvenile should be convicted of . '' The high court in 2005 banned the death penalty for those under 18 who commit aggravated murder . Then , five years later , the justices said juveniles found guilty of non-homicides could not receive life without parole . Now the spotlight turns on the youngest of killers and the question of whether a national consensus has developed to treat them differently regarding a lifetime of incarceration . The separate appeals involve an Alabama boy who , with an accomplice , robbed a neighbor and then beat the man to death and set his house on fire ; and an Arkansas youth who was part of a group of teens who robbed a video store where the clerk was blasted to death with a shotgun . Both were tried and convicted as adults and received the minimum sentences allowed under state law for felony capital murder . There are about 2,500 prisoners serving life sentences without parole for crimes committed as juveniles , at least 79 of whom are 14 years or younger , according to the Equal Justice Initiative , which is representing the two men before the high court . Attorney Bryan Stevenson urged the justices not to `` give up '' on child offenders , who he said are fundamentally different from adults . He said while they must be held accountable for their actions , youths are also works in progress , emotionally and developmentally . `` These deficits in maturity and judgment and decision-making are not crime-specific . All children are encumbered with the same barriers that this court has found to be constitutionally relevant before imposition of a sentence of life imprisonment without parole or the death penalty , '' said Stevenson , who is based in Montgomery , Alabama . `` These differences are even more pronounced in young children . '' Justice Antonin Scalia jumped in . `` Once you depart from the principle that we 've enunciated that ( the ) death ( penalty ) is different , why is life without parole categorically different from 60 years or 70 years ? You 'd be back here next term ( challenging ) a 60-year sentence . '' He wondered aloud whether it would be fair to argue 14-year-olds deserve less time behind bars than a 15-year-old . Stevenson said firmly all those under 18 at the time of their crimes deserve the chance for parole someday . He said the often-terrible facts of a murder can overwhelm any mitigating factors like a defendant 's age , especially for jurors who may be unaware that a young person 's brain development , living environment and self-control are often not complete . `` You would say that a person of 17 years and 11 months , who commits the worst possible string of offenses -- and demonstrates great maturity -- still can not be sentenced to life imprisonment without parole ? '' asked Alito , sounding skeptical . `` What justifies an absolute ban at a certain age and a modified ban above an age ? '' added Justice Ruth Bader Ginsburg . Scalia said 39 states allow juveniles to receive life without parole for certain murder offenses . `` The American people have decided that that 's the rule . They allow it . And the federal government allows it . So I 'm supposed to impose my judgment on what seems to be a consensus of the American people ? '' Later , the Alabama solicitor general said states deserve discretion to set punishments for the worst of offenders , even teenagers . `` The government 's primary goal here is expressing the retributive judgment about the wrongfulness of murder and why it 's different , '' said John Neiman Jr. `` They do n't want to roll the dice on convicted murderers . Society acts with particular revulsion when a convicted murderer commits a crime again '' after being released from custody , he said . `` How do you go back to justifying , '' said Justice Sonia Sotomayor , `` the mandatory nature of life imprisonment without parole , given that not every juvenile is equal and not every murder is equal with respect to them ? '' Justice Stephen Breyer pressed the question further , asking , `` What 's the minimum age , in your opinion , or is there any constitutional minimum at all in respect to which you could give '' life without parole to a young killer . `` I mean , you could have an instance of a 10-year-old or an 8-year-old . I mean , is it totally up to the states , or is there a minimum ? '' Breyer said . Neiman ran into trouble when backed into this legal corner , suggesting , `` If I were the state up here trying to defend a 12-year-old ( getting life without parole ) , I would argue that that was the line . So a 12-year-old -- well , no -- well , yes , '' he finally decided . `` Do you see the difficulty ? All right . So now put yourself in my position , '' responded Breyer . `` Do you want to say 12 ? Do you want to say 10 ? Do you want to say 9 ? Because as soon as whatever you say , I 'm going to say : and why not 14 ? '' he added . Justice Anthony Kennedy -- as he has in many divided cases -- may prove to be the deciding vote . But he seemed troubled about articulating an appropriate age limit . `` Now , we have some quite compelling stories of rehabilitation in this case . I do n't know if they 're isolated ; I do n't know where they are in the statistical universe of how often rehabilitation is demonstrated and is real . What do I look at ? What 's a judge supposed to do ? '' he asked Stevenson . `` You 're just forcing us into a bipolar position . We 're either going to say that you ca n't prevail at all or that everyone under 18 can not get life without parole . I do n't see this middle course . '' Complicating matters , several justices noted differences between the two cases before them . Neiman noted the murder committed by Evan Miller in Alabama was especially `` gruesome . '' The boy and his accomplice had smoked marijuana with the victim in his trailer . The 52-year-old man burned to death after the mobile home was set ablaze . In Kuntrell Jackson 's case , he was originally outside as a lookout when the Chickasaw County , Arkansas , robbery took place . It was a 15-year-old boy who shot the female clerk when she refused to turn over money . The actual shooter later pleaded guilty and received life with the possibility of parole . Stevenson said there was a real question whether Jackson had an `` intent to kill '' during the botched robbery , perhaps allowing for a lesser sentence . But the Arkansas assistant attorney general said the sentence of life without parole was still appropriate , arguing the defendant could have received the death penalty if he had been an adult at the time of the crime . `` A legislative judgment has been made with regard to drawing a baseline for all murderers , whether they are juvenile murderers , whether they are getaway drivers , '' said Kent Holt . `` And when you counsel or aid or do anything that gets you liability for being a capital murderer , then that is the minimum sentence '' -- life without parole , with no exceptions . The cases are Miller v. Alabama ( 10-9646 ) and Jackson v. Hobbs ( 10-9647 ) . Rulings are expected within the next three months .
The Supreme Court looks at two killings for which year - olds were convicted . ` ` What 's the definition of a child ? '' asked Justice Samuel Alito . The high court in 2002 abolished the death penalty for anyone under age 18 .