Lawyers for two prisoners sentenced to life in prison for murders committed when they were age 14 are urging the U.S. Supreme Court to accept their cases and strike down their sentences as unconstitutional.

The lawyers want the Supreme Court to extend its Graham v. Florida decision that held unconstitutional life sentences for juveniles who were convicted of crimes other than murder, the New York Times reports. The lawyers say life sentences without parole should be banned for all offenders who were 13 and 14 when they committed their crimes.

In one of the cases, Kuntrell Jackson of Arkansas received a life sentence for the death of a video store clerk in an armed robbery. Jackson was 14 at the time; another youth killed the clerk. In the other case, Evan Miller of Alabama received a life sentence after he and another youth beat a neighbor and set fire to his home. The neighbor died of smoke inhalation. Miller was also 14 at the time.

Their lawyers may be following a two-step strategy used to eliminate the juvenile death penalty, the Times says. In the Jackson and Miller cases, lawyers are asking to ban life sentences for those 14 and under at the time of their offenses; the decision could be extended to apply to older juveniles in a later case. The Supreme Court eliminated the juvenile death penalty in two stages, first banning it for those under 16 and then for those under 18.