In the 2009 case of Joe Harris Sullivan v. Florida, the U.S. Supreme Court examined whether sentencing a juvenile to life imprisonment without parole for a non-homicidal crime violated the Eighth Amendment's prohibition against cruel and unusual punishment. At age 13, Sullivan was convicted of sexual battery in Florida and sentenced to life in prison with no possibility of parole. The court ruled that such sentences are unconstitutional for juveniles who have not committed homicide due to their lack of maturity and underdeveloped sense of responsibility compared to adults, as well as their potential for growth and rehabilitation. This decision built upon previous rulings that had established certain protections for juvenile offenders under the Eighth Amendment.

In the case of Joe Harris Sullivan v. Florida, Justice Stevens, joined by Justices Ginsburg and Sotomayor in dissenting opinion, argued that sentencing a juvenile offender to life imprisonment without parole for a non-homicide crime is cruel and unusual punishment under the Eighth Amendment. They contended that such severe sentences are disproportionate when applied to children due to their lack of maturity and potential for change. The dissent also highlighted international consensus against this practice as further evidence of its unconstitutionality. Moreover, they disagreed with the majority's view on 'proportionality', arguing it should be considered in terms not only of severity but also duration - thus making life sentences without parole particularly harsh for young offenders who will spend more years behind bars than adult counterparts sentenced later in life.