This week, the Supreme Court heard arguments in a case featuring two convicted murderers who committed their crimes when they were just 14 years old. Sentenced to life in prison without parole, the killers argue that the sentences amount to a violation of the Eighth Amendment, which bars cruel and unusual punishment. The case is just the latest to showcase the court's evolution on juvenile punishment — the Supreme Court abolished the juvenile death penalty in 2005, and barred life without parole for crimes other than murder in 2010. Here, a guide to the latest debate:

How many teen convicts face life without parole? 
Across the nation, around 2,300 life-without-parole inmates committed their lethal crimes before they were 18, and 79 of those did before they were 14. The federal government and 39 states allow such sentences, and some states mandate life without parole for murder, regardless of age.

In this case, what were the boys convicted of?
Kuntrell Jackson of Blytheville, Ark., tried to rob a video store in 1999 with a group of friends. When the clerk threatened to call the police, one of Jackson's friends killed the employee with a shotgun. At sentencing, Jackson was judged to have played a large enough role in the killing to receive a life sentence without parole. The other plaintiff, Evan Miller of Lawrence, Ala., tried to rob a neighbor. When the neighbor fought back, Miller and his friend beat him with baseball bats and set his house on fire, killing him.

What is their argument?
Their lawyer, Bryan Stevenson, says juveniles are less to blame for their crimes than adults are. Teens are more vulnerable to peer pressure and more inclined to engage in reckless behavior, he argues, because their capabilities of judgment are not fully formed.

What did Arkansas and Alabama say?
Alabama Solicitor General John Neiman said the court must respect states' decisions to dole out these sentences, which he claimed were "in line with the national consensus" and "morally justified." Arkansas Assistant Attorney General Kent Holt said, "The punishment for this crime reinforces the sanctity of human life and it expresses the state's moral outrage."

How did the justices react?
Conservative Justice Antonin Scalia said "the American people" have already decided that the sentence is just, given that 39 states and the federal government allow it. Justice Ruth Bader Ginsburg, a liberal, scoffed at the idea that the punishment preserves the "sanctity" of life, saying the sentence turns a teenage criminal into a "throwaway person." However, all eyes were on Justice Anthony Kennedy, the court's swing vote, who was clearly "searching for a means" to strike down the sentence, says Warren Richey at The Christian Science Monitor.

How is the court expected to rule?
There are several possibilities. On the extremes, the court could very well uphold the punishments, or strike them down. In a compromise, the court could nullify mandated life-without-parole sentences, which would give courts greater discretion at trial. The court could also make a distinction between teenage criminals, preserving the punishment for 18-year-olds, but barring it for 14-year-olds. The court is expected to deliver its decision in the summer. 

Sources: Associated PressThe Christian Science MonitorThe New York Times, The Washington Post