[5] The Los Angeles Times wrote: "In one case that came before the court, Kuntrell Jackson was 14 in November 18, 1999 when he and two other teenagers went to a video store in Arkansas planning to rob it.

In the second case, Evan Miller, a 14-year-old from Alabama, was convicted of a July 15, 2003, murder after he and another boy set fire to a trailer where they had bought drugs from a neighbor.

[3][9] Justice Elena Kagan wrote for the majority of the court "that mandatory life without parole for those under age of 18 at the time of their crime violates the 8th Amendment’s prohibition on cruel and unusual punishments".

[3] Justice Kagan said: 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.

It prevents taking into account the family and home environment that surrounds him – and from which he cannot usually extricate himself – no matter how brutal or dysfunctional.

[5]Chief Justice John Roberts voiced in his dissent the opinion that mandatory life sentences "could not plausibly be described" as unusual when a majority of states endorse them.

He wrote: "Determining the appropriate sentence for a teenager convicted of murder presents grave and challenging questions of morality and social policy.

Alito wrote of the consequences of the majority ruling: Even a 17+1⁄2-year-old who sets off a bomb in a crowded mall or guns down a dozen students and teachers is a 'child' and must be given a chance to persuade a judge to permit his release into society.

The Supreme Court had granted the case Mathena v. Malvo in March 2019, and heard oral argument in October 2019.

[18] A year later, the Supreme Court granted a related case, Jones v. Mississippi, involving a person who had killed his grandfather when he was 15 in 2004 and given the mandatory sentence of life without parole.

The state noted Slocumb had failed to complete any educational courses or enroll in any rehabilitative programs while incarcerated.