Tuesday, a lawyer for Montgomery argued that the justices should take a case they decided three years ago, and retroactively apply it to his situation. If the court agrees, Montgomery, 69, could get a new sentencing hearing. The ruling could also affect about 2,000 similarly situated inmates in several states.
Justice Elena Kagan, writing for the majority, said 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."
Lawyers for Montgomery argue that that case should apply to him, even though he committed his crime well before that ruling.
"Mr. Montgomery remains incarcerated based upon a constitutionally disproportionate sentence that could not be imposed today," his lawyer, Mark Plaisance argued in court filings.
But before the Supreme Court can decide whether Miller applies to Montgomery, the justices must decide a threshold question: whether the court has the authority to hear the case in the first place. Tuesday, several justices had serious questions about their jurisdiction raising the question that the court might not reach the merits of the case.
While all the parties before the court -- Montgomery, the state of Louisiana and the federal government - believe the it does have jurisdiction to hear the case, before oral arguments, the justices appointed a third-party attorney, Richard D. Bernstein, to present the other side. Bernstein said the justices didn't have jurisdiction to review the opinion rendered by the Louisiana Supreme Court because the retroactivity question is governed by state, not federal law.
Justice Antonin Scalia appeared to be the most skeptical of the court's ability to hear the case. He said that the Louisiana Supreme court said, "this is a matter of State law." As lawyers tried to move on to the merits, the justices several times circled back to the issue of jurisdiction.
Does it apply retroactively?
S. Kyle Duncan, a lawyer representing Louisiana, argued that Miller does not apply to Montgomery in part because the Miller opinion was an "incremental step in sentencing juveniles."
In general, the court's decisions on criminal law don't normally apply retroactively. But court precedent allows exceptions if the new rule is considered substantial.
Duncan said it was not a major change in part because life without parole sentences are still available as a sentence.
In addition, Duncan argued that if the court were to apply the case retroactively it would require the re-litigation of facts that over time have been lost.
Louisiana says that virtually everyone involved in Montgomery's trial is dead and that there-sentencing process would force the family members of the victims to relive their trauma.
In court, Deputy Solicitor General Michael R. Dreeben supported Montgomery. Dreeben argued that Miller should apply retroactively because it was not just a procedural rule change. "In our view," he said, "it goes far beyond merely regulating the procedure by which youths are sentenced for homicide crimes," he said. " It compelled the State to adopt new substantive sentencing options , an option that is less severe than life without parole," he said.
Kagan seemed to agree with Montgomery. She noted that while life without parole as a sentence was still on the table, the state of play had changed significantly. "What the Court has done is to say, there have to be other options. There has to be an option of ten years or five years or two years—whatever it is. "Kagan said the sentences now are different and are defined both by the "upper end" and the "lower end."
When he committed the crime, Montgomery, an African-American, was in 11th grade playing hooky from school. He was surprised by Sheriff Deputy Charles Hurt, who was white, and he shot him. Although originally sentenced to death, the Louisiana Supreme Court overturned the conviction in part due to the atmosphere around the trial including Ku Klux Klan activity. In 1969, he was retried and once again found guilty of murder, but received a mandatory sentence of life without parole.
Hurt left behind a wife and three young children. One of his daughters, Becky Wilson, has filed a brief in support of Louisiana.
Wilson, joined by the National Association of Victims of Juvenile Murderers, argues that while she has forgiven Montgomery, "people should pay the consequences of their actions."
In court briefs her lawyers say that if the court rules in favor of Montgomery, Wilson and other surviving family members of other victims will be forced to "relive the events that traumatized them in the first instance.'
"These surviving family members deserve no less respect than the juvenile murderers," the lawyers wrote.