The crimes punishable by death in the United States fall into three systems: state law, federal law, and the military justice system. At the state level, capital punishment is almost always reserved for aggravated forms of first-degree murder in the 27 states that still authorize it. Federal law lists more than 40 death-eligible offenses, but nearly all of them involve a killing or a direct threat to national security. The military has its own list under the Uniform Code of Military Justice. Across all three systems, the Supreme Court has placed firm constitutional limits on who can be executed and for what.
State Capital Crimes
Of the 27 states that authorize capital punishment, nearly all restrict it to aggravated first-degree murder. A straightforward intentional killing, even if premeditated, typically does not qualify on its own. The prosecution has to prove at least one statutory aggravating circumstance that pushes the crime beyond an ordinary homicide.
The aggravators that appear across most state statutes include:
- Murder for hire, meaning either paying someone to kill or being the hired killer
- Murder of a child, with specific age thresholds that vary by state and often sit under 12 or 14
- Murder of a law enforcement officer, either on duty or because of the officer’s role
- Felony murder, where a killing occurs during another dangerous crime such as robbery, kidnapping, or sexual assault
- Multiple victims killed in a single episode or as part of a pattern
- Torture or extreme cruelty inflicted before the killing
Some states keep the death penalty on the books but have paused executions. California (2019), Oregon (2011), and Pennsylvania (2015) each operate under a governor-imposed moratorium, and Ohio has maintained an unofficial moratorium since 2019 over lethal injection concerns. A jury in those states can still return a death sentence, but no execution will be carried out while the moratorium stands.
Federal Capital Crimes
Federal capital offenses apply nationwide, which means they can be charged regardless of state lines or whether the state where the crime happened authorizes capital punishment. They fall into three broad groups: offenses against national security, homicides committed under federal jurisdiction, and certain large-scale drug trafficking.
Treason and Espionage
Treason is the only crime specifically defined in the Constitution. Anyone who owes allegiance to the United States and wages war against it, or who gives aid and comfort to its enemies, faces either death or a minimum of five years in prison and a fine of at least $10,000.1Office of the Law Revision Counsel. 18 USC 2381 – Treason A conviction also permanently bars the person from holding any federal office.
Espionage can trigger the death penalty, but only under specific conditions. Transmitting national defense information to a foreign government is death-eligible when a jury finds that the offense led to the identification and death of an American intelligence agent, or that the information directly concerned nuclear weapons, military satellites, early warning systems, war plans, or cryptographic intelligence.2Office of the Law Revision Counsel. 18 USC 794 – Gathering or Delivering Defense Information to Aid Foreign Government During wartime, the threshold drops, and gathering or delivering defense information can carry the death penalty without those additional findings.
Murder Under Federal Jurisdiction
First-degree murder in areas of special federal jurisdiction, such as military bases, national parks, and federal buildings, is punishable by death or life imprisonment.3Office of the Law Revision Counsel. 18 USC 1111 – Murder Killing a federal officer or employee during or because of their official duties is prosecuted under the same statute.4Office of the Law Revision Counsel. 18 USC 1114 – Protection of Officers and Employees of the United States
A death during dozens of other federal crimes can also trigger capital charges. The list includes kidnapping, hostage-taking, terrorism abroad against U.S. nationals, violence against members of Congress or Supreme Court justices, train wrecking, maritime violence, and destruction of aircraft or government property with explosives.5Congress.gov. Federal Capital Offenses – An Overview of Substantive and Procedural Law In each case, the death penalty becomes available because someone died as a result of the underlying crime.
Terrorism and Weapons of Mass Destruction
Using or conspiring to use a weapon of mass destruction is punishable by death when the attack kills someone, whether the attack happens inside the United States or is carried out by a U.S. national abroad.6Office of the Law Revision Counsel. 18 USC 2332a – Use of Weapons of Mass Destruction Aircraft hijacking that results in a death carries a mandatory sentence of either death or life imprisonment.7Office of the Law Revision Counsel. 49 USC 46502 – Aircraft Piracy
Drug Kingpin Offenses
Large-scale drug trafficking can become a capital crime under two narrow circumstances. The first requires a continuing criminal enterprise involving at least twice the drug quantity or twice the gross revenue thresholds set by the Controlled Substances Act. The second covers a principal leader of such an enterprise who directs or attempts to kill a public officer, juror, witness, or their family members to obstruct an investigation.8Office of the Law Revision Counsel. 18 USC 3591 – Sentence of Death These are among the very few federal capital offenses that do not require a victim’s death, though the second scenario involves attempted murder.
Military Capital Crimes
The military justice system operates under the Uniform Code of Military Justice and prosecutes capital cases through courts-martial rather than civilian courts. No service member has been executed since 1961, when Army Private John Bennett was hanged at Fort Leavenworth.
Premeditated murder by a service member carries a mandatory sentence of either death or life imprisonment under UCMJ Article 118.9Office of the Law Revision Counsel. 10 USC 918 – Art 118 Murder Spying during wartime stands apart from every other military capital offense because the statute imposes a mandatory death sentence with no alternative. Anyone found lurking or acting as a spy in or around military-controlled areas, shipyards, or industrial plants supporting the war effort faces execution upon conviction.10Office of the Law Revision Counsel. 10 USC 906 – Art 106 Spies
Desertion during wartime is punishable by death at the court-martial’s discretion. During peacetime, the death penalty is not available for desertion.11Office of the Law Revision Counsel. 10 USC 885 – Art 85 Desertion Mutiny and sedition follow the same pattern. Anyone who refuses orders in concert with others to override military authority, or who creates a revolt against lawful civil authority, can be sentenced to death, and even failing to suppress or report a mutiny you know about is covered by the same statute.12Office of the Law Revision Counsel. 10 USC 894 – Art 94 Mutiny or Sedition
A military death sentence cannot be carried out without explicit presidential authorization. After all judicial appeals are exhausted, the case moves to the executive branch, and the president must sign an affirmative order approving the execution before it can proceed.
Who Cannot Be Executed, and for What
The Eighth Amendment bars “cruel and unusual punishments.”13Library of Congress. US Constitution – Eighth Amendment The Supreme Court has used that language to impose categorical limits that override any federal or state statute to the contrary.
In Roper v. Simmons (2005), the Court held that the Eighth and Fourteenth Amendments forbid executing anyone who was under 18 at the time of their crime. The majority found that minors have diminished culpability and greater capacity for change, making the death penalty disproportionate for them.14Justia U.S. Supreme Court Center. Roper v Simmons, 543 US 551
Three years earlier, Atkins v. Virginia (2002) established that executing a person with an intellectual disability violates the same constitutional standard. Courts must evaluate a defendant’s cognitive functioning and adaptive behavior before a death sentence can stand.15Justia U.S. Supreme Court Center. Atkins v Virginia, 536 US 304
Kennedy v. Louisiana (2008) drew a bright line on the type of crime: the death penalty cannot be imposed for any crime against an individual where the victim did not die and the defendant did not intend to cause death. The case involved the rape of a child, and the Court ruled that execution was disproportionate even for that offense.16Legal Information Institute. Kennedy v Louisiana The ruling left open the possibility that crimes against the state, such as treason and espionage, may still carry the death penalty without a resulting death.
How a Death-Eligible Crime Becomes a Death Sentence
Being charged with a capital crime does not automatically mean a death sentence. Capital trials are split into two phases. The first works like any criminal trial: the jury decides guilt. If the defendant is convicted on the capital charge, the same jury then sits for a separate sentencing hearing to weigh aggravating and mitigating factors. This two-step structure exists because the Supreme Court requires it as a safeguard against arbitrary death sentences.
Federal law spells out aggravating factors for different categories of capital offenses. For homicides, they include killing during another federal crime such as kidnapping or carjacking, especially cruel or depraved conduct involving torture, prior violent felony convictions, creating a grave risk of death to people beyond the immediate victim, murder for hire, and targeting a vulnerable victim. For espionage and treason, aggravators focus on prior espionage convictions, grave risk to national security, and grave risk of death.17Office of the Law Revision Counsel. 18 USC 3592 – Mitigating and Aggravating Factors to Be Considered in Determining Whether a Sentence of Death Is Justified State statutes contain their own lists, which overlap substantially but vary in specifics.
Mitigating evidence is not limited to a fixed list. The Supreme Court has ruled that a jury may consider any mitigating evidence a juror finds relevant. Common examples include a history of mental illness, childhood abuse or neglect, the defendant’s age, the absence of a prior criminal record, remorse, and a relatively minor role in the killing.
At the federal level, the jury must be unanimous to recommend death. If jurors collectively find that the aggravating factors sufficiently outweigh the mitigating factors, they may recommend a death sentence. If even one juror disagrees, the court must impose a lesser sentence, typically life without the possibility of release.18Office of the Law Revision Counsel. 18 USC 3593 – Special Hearing to Determine Whether a Sentence of Death Is Justified State unanimity requirements vary, though most death-penalty states require a unanimous jury for a death sentence.