In the landmark decision in Roper v. Simmons, issued on March 1, 2005, the United States Supreme Court ruled 5-4 that it is unconstitutional to impose the death penalty for a crime committed by a child under the age of 18. The Court ruled that a death sentence imposed on a minor violates the Eighth and Fourteenth Amendments.
In his opinion for the majority, Justice Kennedy wrote, “When a juvenile offender commits a heinous crime, the state can exact forfeiture of some of the most basic liberties, but the state cannot extinguish his life and his potential to attain a mature understanding of his own humanity.” Roper v. Simmons, No. 03-633, 543 U.S. _ (slip op. at 20) (2005)
The Court cited adolescent development research finding that children’s brains—not just their bodies—are not fully developed, and as a result, they do not have adult levels of judgment or ability to assess risks and the consequences of their actions. The Court noted that children are more susceptible to peer pressure than adults and have little power to escape harmful environments. Because of where they are developmentally, children also have greater potential for rehabilitation. The Court concluded that children are categorically less culpable than adults.
Justice Kennedy wrote, “From a moral standpoint, it would be misguided to equate the failings of a minor with those of an adult, for a greater possibility exists that a minor’s character deficiencies will be reformed.” Roper v. Simmons, No. 03-633, 543 U.S. _ (slip op. at 16) (2005)
In addition, the Court discussed the infrequency with which states were imposing the death penalty on children and looked at the practices in other countries and that the United States stood alone in allowing the execution of children. Significantly, the Court also noted that the imposition of the death penalty on a child violated international human rights laws, including the Convention on the Rights of the Child and the International Covenant on Civil and Political Rights.