In Roper v. Simmons, 543 U.S. 551 (2005), the Supreme Court held that the Eighth and Fourteenth Amendments prohibit executing anyone who was under eighteen at the time of the crime. The 5–4 decision, issued on March 1, 2005, ended the juvenile death penalty in the United States and invalidated the death sentences of 72 people held on death rows in 20 states.1Justia. Roper v. Simmons
The Crime and the Original Death Sentence
On September 9, 1993, seventeen-year-old Christopher Simmons and an accomplice broke into Shirley Crook’s home in Jefferson County, Missouri. They bound her with duct tape and electrical wire, drove her to Castlewood State Park in her own minivan, and threw her from a railroad trestle into the Meramec River, where she drowned. Simmons had planned the crime in advance and later bragged to classmates that he would get away with it because he was a minor.1Justia. Roper v. Simmons
Because Simmons was seventeen, Missouri tried him as an adult. A jury convicted him of first-degree murder and, after finding three aggravating factors, recommended a death sentence. The trial judge imposed it.2Justia. State v. Simmons
How the Case Reached the Supreme Court
Simmons’ death sentence held for nearly a decade. Then, in 2002, the Supreme Court decided Atkins v. Virginia, which barred executing people with intellectual disabilities on the ground that their reduced culpability made the death penalty a disproportionate response.3Justia. Atkins v. Virginia Simmons’ lawyers argued that the same logic applied to juveniles, whose brains are still developing.
The Missouri Supreme Court agreed. It counted the states that had rejected the juvenile death penalty since Stanford v. Kentucky in 1989 had allowed executions for offenders as young as sixteen,4Library of Congress. Stanford v. Kentucky found that thirty states now prohibited the practice, vacated Simmons’ death sentence, and resentenced him to life without parole. The state appealed to the U.S. Supreme Court.
The Court’s Reasoning
Justice Anthony Kennedy wrote the majority opinion, joined by Justices Stevens, Souter, Ginsburg, and Breyer.1Justia. Roper v. Simmons The opinion rested on three grounds.
A National Consensus Against Juvenile Executions
Applying the Eighth Amendment’s “evolving standards of decency” test, the Court looked to state legislation as the primary evidence of contemporary values.5Cornell Law Institute. Evolving Standard Thirty states prohibited the juvenile death penalty, either by abolishing capital punishment entirely or by excluding offenders under eighteen. Since Stanford, eight states had raised their minimum execution age. That trend, the Court concluded, tracked the same pattern it had relied on in Atkins and pointed to a genuine national consensus.6Supreme Court of the United States. 543 U.S. 551 – Roper v. Simmons
Three Categorical Differences Between Juveniles and Adults
Kennedy identified three reasons juveniles are less culpable than adults as a class. They lack maturity and a fully developed sense of responsibility, which leads to impulsive decisions. They are more vulnerable to negative influences and peer pressure, in part because they have less control over their own environment. And their characters are not yet fully formed, so personality traits during adolescence are more transitory than fixed.1Justia. Roper v. Simmons
Those differences carry two consequences. Reduced culpability makes the death penalty disproportionate, even for a serious crime. And because a young person’s character is still developing, the retributive rationale for execution weakens: the person executed years later may bear little resemblance to the teenager who committed the crime. Scientific research submitted by the American Psychological Association and other groups reinforced the point, describing brain development through young adulthood in regions tied to decision-making, impulse control, and risk assessment.7American Psychological Association. Roper v. Simmons
International Practice
Kennedy also noted that the United States stood alone as the only country that continued to officially sanction the juvenile death penalty. The Court treated international treaties and foreign laws as confirmatory rather than binding, but the reference became one of the opinion’s most contested features.6Supreme Court of the United States. 543 U.S. 551 – Roper v. Simmons
The Dissents
Justice Antonin Scalia, joined by Chief Justice Rehnquist and Justice Thomas, accused the majority of substituting its own moral judgment for that of the American people. He wrote that the Court had proclaimed itself “sole arbiter of our Nation’s moral standards” while “purport[ing] to take guidance from the views of foreign courts and legislatures,” and said foreign approval “has no place in the legal opinion of this Court.”8Cornell Law Institute. Roper v. Simmons – Scalia Dissent Twenty states still permitted juvenile executions, Scalia argued, and juries were already equipped to weigh youth as a mitigating factor case by case. A categorical ban, in his view, ignored defendants like Simmons whose crimes showed deliberation and cruelty.
Justice Sandra Day O’Connor wrote a separate dissent focused on the consensus analysis. She acknowledged the trend away from juvenile executions but found the evidence too thin to justify overruling Stanford so soon after the Court had reaffirmed it, and she urged restraint on “genuinely contested” moral questions.9Cornell Law Institute. Roper v. Simmons – O’Connor Dissent
What the Ruling Changed
The decision immediately invalidated 72 death sentences in 20 states. In the modern death penalty era beginning in 1976, twenty-two juvenile offenders had already been executed before Roper closed the practice for good. The Court’s bright-line rule at age eighteen eliminated case-by-case discretion on this question. No state may execute a person for a crime committed as a minor, whatever the facts of the crime.
Simmons himself was resentenced to life without parole and remains incarcerated in Missouri.
The Cases That Built on Roper
Kennedy’s premise, that young people are categorically less culpable because of developmental differences, became the foundation for a line of decisions that progressively restricted the harshest sentences for minors.
- Graham v. Florida (2010) held that life without parole for a juvenile who commits a non-homicide offense violates the Eighth Amendment. States must offer such offenders “some meaningful opportunity for release based on demonstrated maturity and rehabilitation.”10Justia. Graham v. Florida
- Miller v. Alabama (2012) struck down mandatory life-without-parole sentences for juvenile homicide offenders, requiring sentencing courts to consider the defendant’s age, background, and circumstances before imposing the harshest available sentence.11Justia. Miller v. Alabama
- Montgomery v. Louisiana (2016) made Miller retroactive, requiring states to resentence or offer parole hearings to juvenile offenders already serving mandatory life sentences.
- Jones v. Mississippi (2021) clarified that a sentencing judge need not make a separate factual finding of “permanent incorrigibility” before imposing life without parole on a juvenile, provided the sentencing scheme is discretionary rather than mandatory.12Supreme Court of the United States. Jones v. Mississippi
Roper established the principle. Graham, Miller, and Montgomery extended it. Jones drew a limit. Running through all of them is Kennedy’s core idea: young people are different, and the Constitution requires the justice system to account for those differences when it reaches for its most severe punishments.