Final answer:
The Supreme Court has decided that the death penalty may not be applied to individuals who were under the age of 18 when they committed the crime, following the Roper v. Simmons case in 2005.
Step-by-step explanation:
The Supreme Court has issued rulings that limit the application of the death penalty. For instance, the death penalty may not be applied to those who were under 18 when they committed a crime. This is outlined in the case of Roper v. Simmons (2005), where the Court ruled that it is unconstitutional to impose capital punishment for crimes committed by individuals under 18 years of age. The Court has generally rejected the death penalty for crimes that did not result in death, with exceptions such as certain acts of terrorism or murder.
Additionally, execution of individuals with cognitive disabilities is deemed 'cruel and unusual punishments' as prohibited by the Eighth Amendment, following the Atkins v. Virginia (2002) ruling. The Supreme Court has thus ensured ongoing scrutiny of the death penalty's application, reflecting evolving standards of decency in American society.