In a sensitive and controversial case that had repercussions well beyond the bench, a very divided (5-4) U.S. Supreme Court ruled in 2005 that executing a convicted murderer whose capital crime was committed at the age of 17 constituted "cruel and unusual punishment" under the Eighth Amendment. The decision in Roper v. Simmons, overruled an earlier Court decision (Stanford v. Kentucky). Further, as applicable to the states under the Fourteenth Amendment, the decision rendered several state laws unconstitutional, causing those states (12 in all) to reverse sentences for 72 prisoners on death row who were under 18 at the time of committing capital crimes. As of 2005, at least 20 of 38 states with the death penalty had permitted its application to offenders less than 18 years old.

Prior to this decision, there had been two key court cases that had laid the foundation for juveniles to receive the death penalty.

In Thompson v. Oklahoma (1988), the Supreme Court overturned a death sentence for a juvenile who was 15 years old at the time he was involved in a murder. The opinion cited the failure of the state of Oklahoma to stipulate a minimum age for execution. This case has also set the minimum age of 16 at which a juvenile can be executed.

In Stanford v. Kentucky (1989), the Supreme Court ruled that it was constitutional for a state to execute a juvenile who was between the ages of 16 and 18 at the time of the offense but unconstitutional if the juvenile was under 16.

Although there have been a number of challenges to the minimum age of 16 for juvenile execution set by Thompson v. Oklahoma, such as State v. Stone (LA, 1988), Flowers v. State, (AL, 1991) and Allen v. State (FL, 1994), these challenges have only gone as far as the court of appeals.

More than 360 juveniles have been executed over the years, beginning with Thomas Graunger, who was executed in 1642 in Massachusetts. After 1990, the only known countries that execute juveniles are Iran, Pakistan, Yemen, Saudi Arabia, and the United States (www.deathpenaltyinfo.org).