A death sentence is a court order authorizing the government to execute a person convicted of a qualifying crime, and it is the most severe punishment available in the American legal system. Twenty-seven states, the federal government, and the U.S. military currently allow capital punishment. Roughly 2,100 people sit on death row nationwide, and only a small number of executions are carried out in any given year. Federal procedures governing eligibility, sentencing hearings, appeals, and the execution itself are codified in Chapter 228 of Title 18 of the U.S. Code.1Office of the Law Revision Counsel. 18 USC Ch 228 – Death Sentence
Which Crimes Qualify
Federal law makes a death sentence available in two broad categories. The first covers treason and espionage, where no one necessarily dies but the threat to national security is extreme. Treason alone carries a possible death sentence or a minimum of five years in prison.2Office of the Law Revision Counsel. 18 USC 2381 – Treason The second category covers offenses where someone is intentionally killed and specific additional conditions are met, such as the killing occurring during another serious crime or the defendant having a prior violent felony conviction.3Office of the Law Revision Counsel. 18 USC 3591 – Sentence of Death
Large-scale drug trafficking can carry the death penalty under federal law, but the threshold is higher than most people assume. Running a big operation isn’t enough. The penalty applies when a principal leader of a trafficking enterprise either directs an intentional killing or personally kills someone during the operation.4Office of the Law Revision Counsel. 21 USC 848 – Continuing Criminal Enterprise
State capital crimes are narrower. Nearly every state that retains the death penalty limits it to first-degree murder committed under aggravating circumstances: killing multiple people, killing for hire, killing a law enforcement officer, or committing murder during another felony like robbery or kidnapping. In 2008, the Supreme Court ruled in Kennedy v. Louisiana that the Eighth Amendment forbids executing someone for a crime against an individual that did not result in the victim’s death.5Legal Information Institute. Kennedy v Louisiana That ruling effectively limits state death sentences to murder cases, with narrow exceptions for crimes against the state like treason.
When a crime falls under both state and federal jurisdiction, such as the murder of a federal officer, prosecutors decide which system will pursue the case based on the evidence and which set of charges offers the stronger path to conviction.
Who Cannot Be Sentenced to Death
The Supreme Court has drawn categorical lines around capital punishment, removing entire groups of people from eligibility regardless of what they did. Three exemptions are firm:
- Juveniles. No one who was under 18 at the time of the crime can be sentenced to death. The Court held in Roper v. Simmons (2005) that executing juvenile offenders violates the Eighth and Fourteenth Amendments. The federal statute incorporates the same bar.6Justia Law. Roper v Simmons, 543 US 551 (2005)3Office of the Law Revision Counsel. 18 USC 3591 – Sentence of Death
- Intellectual disability. The Court held in Atkins v. Virginia (2002) that executing people with intellectual disabilities is unconstitutional. States were given some latitude to define the clinical criteria, but the Court later ruled that states cannot rely on rigid IQ cutoffs or outdated stereotypes and must follow accepted medical standards.
- Mental incompetence at the time of execution. Under Ford v. Wainwright (1986), a prisoner who cannot understand the punishment or why it was imposed cannot be executed, even if they were competent during trial. If a death-row prisoner’s mental state deteriorates, the execution must be stayed until competency is restored.
The modern death penalty framework itself traces to a Supreme Court intervention. In Furman v. Georgia (1972), the Court ruled that the death penalty as then practiced was so arbitrarily imposed that it amounted to cruel and unusual punishment, halting every execution in the country.7Justia Law. Furman v Georgia, 408 US 238 (1972) Four years later, executions resumed under restructured state laws requiring guided jury discretion and automatic appellate review. Every modern death penalty statute operates within that framework.
How a Death Sentence Is Decided
Capital cases follow a different structure than other criminal prosecutions. The process involves special jury screening, a two-stage trial, and a set of statutory factors that shape the final decision.
Death-Qualified Juries
Before the trial starts, prospective jurors go through an extra screening called death qualification. Each person is questioned individually about their views on capital punishment. Anyone whose opposition would prevent them from ever voting for a death sentence is removed, as is anyone who would impose death automatically without considering the evidence. The Supreme Court set that standard in Witherspoon v. Illinois (1968), holding that a death sentence cannot stand if the jury was selected by excluding people simply because they voiced general objections to capital punishment.8Justia Law. Witherspoon v Illinois, 391 US 510 (1968) This process adds days or weeks to jury selection.
Guilt Phase and Penalty Phase
The trial itself is split into two stages, a structure the Supreme Court requires for every capital case.9National Institute of Justice. Law 101 – Special Circumstances (Death Penalty) During the guilt phase, the jury decides whether the defendant committed the crime. The rules of evidence work the same as in any criminal trial, and the prosecution must prove guilt beyond a reasonable doubt. Only after a unanimous guilty verdict does the case move forward.
The penalty phase is where the real fight over life and death happens. Both sides introduce evidence that would normally be excluded during the guilt phase: the defendant’s childhood, mental health history, military service, or prior criminal record. The prosecution presents aggravating factors that push toward death. Federal law lists these by offense category and includes prior violent felony convictions, especially cruel conduct, the defendant’s creation of a grave risk of death to bystanders, and the vulnerability of the victim. The defense counters with mitigating evidence: impaired mental capacity, duress, a minor role in the crime, lack of prior criminal history, severe emotional disturbance, or anything else in the defendant’s background that argues against execution.10Office of the Law Revision Counsel. 18 USC 3592 – Mitigating and Aggravating Factors
Family members and others affected by the crime may also testify through victim impact statements. The Supreme Court authorized this evidence in Payne v. Tennessee (1991), reasoning that because defendants can present virtually unlimited mitigating evidence about their own circumstances, the prosecution should be able to show the human cost of the crime.
After hearing all of the evidence, the jury weighs aggravating factors against mitigating factors. A death sentence requires a unanimous vote. If even one juror holds out, the court imposes a lesser sentence, usually life without parole.11Office of the Law Revision Counsel. 18 USC 3593 – Special Hearing to Determine Whether a Sentence of Death Is Justified The Supreme Court has also ruled that the Sixth Amendment requires a jury, not a judge acting alone, to find the aggravating factors necessary for a death sentence.12Legal Information Institute. Ring v Arizona
How Executions Are Carried Out
Every jurisdiction that carries out executions must use a method authorized by its own statutes. Lethal injection is the default in the vast majority of these jurisdictions, though the specific drugs and protocols vary from state to state. Under federal law, the method follows the law of the state where the sentence was imposed. If that state has no death penalty, the court designates another state whose law controls the procedure.13Office of the Law Revision Counsel. 18 USC 3596 – Implementation of a Sentence of Death
Obtaining lethal injection drugs has become a significant practical obstacle. Major pharmaceutical manufacturers have restricted sales to correctional agencies, and European export controls have cut off supplies of key chemicals. Several alternative methods remain legally available:
- Electrocution. Authorized in about nine states, though most offer it only as a backup when lethal injection is unavailable. South Carolina is the only state where electrocution serves as the default method.
- Lethal gas. Also authorized in roughly nine states, all of which use lethal injection as the primary method.
- Firing squad. Available in five states. Idaho plans to make it the primary method beginning in July 2026.
- Nitrogen hypoxia. The newest method. Alabama became the first state to use it in January 2024. Five states currently authorize it, but only Alabama and Louisiana have issued formal protocols.
Appeals, Habeas, and Clemency
A death sentence triggers an automatic, multi-layered review process designed to catch errors before an irreversible punishment is carried out. In most states, the conviction and sentence go directly to the state’s highest court regardless of whether the defendant wants to appeal.
The direct appeal focuses on what happened at trial: whether the judge made legal errors, whether evidence was improperly admitted or excluded, and whether the jury received correct instructions. If the court finds significant problems, it can overturn the conviction, reverse the death sentence alone, or order an entirely new trial.
After the direct appeal is exhausted, defendants can file habeas corpus petitions in state court and then in federal court. These petitions raise issues that weren’t or couldn’t have been addressed at trial: ineffective defense counsel, prosecutorial misconduct, newly discovered evidence, or constitutional violations. Federal habeas review is governed by the Antiterrorism and Effective Death Penalty Act of 1996, which imposed a one-year filing deadline and strict limits on successive petitions.14U.S. Government Publishing Office. Antiterrorism and Effective Death Penalty Act of 1996 The law also requires federal courts to defer to state court rulings unless those rulings involved an unreasonable application of clearly established federal law.
This layered review takes years. More than half of all current death-row prisoners have been waiting longer than 18 years, and the average gap between sentencing and execution reached nearly 19 years as of the most recent federal data.
Even after every court has weighed in, the executive branch can commute a death sentence to life in prison or, rarely, grant a full pardon. At the federal level, only the President holds this power, and the process runs through the Department of Justice’s Office of the Pardon Attorney, which reviews applications and makes recommendations.15United States Department of Justice. Apply for Clemency State procedures vary widely. Some governors have sole authority. Others must first receive a recommendation from a clemency board, and in a few states that recommendation must be unanimous before the governor can act. A handful of states vest clemency authority entirely in a board.
Clemency in capital cases is extraordinarily rare. More than a dozen states with active death penalty statutes have not granted a single clemency since 1976. One notable exception came in December 2024, when President Biden commuted 37 of the 40 federal death sentences to life without parole, consistent with the moratorium his administration had placed on federal executions.
Since 1973, at least 200 people originally sentenced to death have later been exonerated. For the roughly 2,100 people currently on death row, the sentence defines daily life beyond the courtroom: most are held in solitary or near-solitary confinement for 23 hours a day in specialized high-security units. Whether a given sentence ends in execution, commutation, reversal on appeal, or natural death depends on a chain of legal and political decisions that can stretch over decades.