What Is a Crime Against Humanity? Elements, Acts, and Courts

A crime against humanity is a serious attack on civilians — such as murder, extermination, enslavement, torture, sexual violence, enforced disappearance, or persecution — committed as part of a widespread or systematic campaign, with the perpetrator aware that their act forms part of that larger campaign. The definition most courts rely on comes from the Rome Statute of the International Criminal Court, which 125 countries have ratified.¹ Unlike war crimes, these offenses can occur during peacetime. Unlike genocide, they do not require that the victims share a national, ethnic, racial, or religious identity.

The Three Elements That Must Be Present

A single killing, however brutal, is not a crime against humanity. Three elements have to line up before an act crosses from a domestic offense into this category of international crime.

A Widespread or Systematic Attack on Civilians

The conduct has to occur as part of an “attack directed against any civilian population.” The Rome Statute defines that attack as a course of conduct involving the repeated commission of prohibited acts, carried out to further a state or organizational policy.² The attack does not have to be military. A government that systematically imprisons political dissidents and a paramilitary group that carries out mass rapes both fit.

“Widespread” speaks to scale: a large number of victims, or acts spread across a broad area. “Systematic” speaks to organization: the violence follows a plan rather than erupting at random. Only one of the two needs to be shown, though prosecutors often establish both.¹

A State or Organizational Policy

The attack must be tied to a policy pushed by a state or an organization. Direct orders are not required. The policy can be informal — a pattern of tolerance, encouragement, or deliberate inaction qualifies. Non-state actors like armed militias count; it does not have to be a government driving the campaign.

Knowledge of the Attack

The person committing the act must know their conduct is part of the broader attack on civilians. That mental link is what elevates the crime from a domestic matter to an international one.¹ Someone acting in genuine isolation, with no awareness of any larger campaign, would not be liable under this category, though they could still be prosecuted for the underlying offense under ordinary domestic law.

The Acts That Qualify

The Rome Statute lists eleven categories of conduct that count as crimes against humanity when carried out in the context of a widespread or systematic attack on civilians.¹

Murder — intentional killing of one or more persons.
Extermination — deliberately inflicting conditions designed to destroy part of a population, such as cutting off food, water, or medicine.
Enslavement — exercising powers of ownership over a person, including trafficking.
Deportation or forcible transfer — forcing people from the area where they lawfully live, whether across borders or within a country.
Imprisonment — severe deprivation of liberty in violation of fundamental international rules, such as mass arbitrary detention without charge.
Torture — intentionally causing severe physical or mental suffering to someone in custody or under the perpetrator’s control.
Sexual violence — rape, sexual slavery, forced prostitution, forced pregnancy, forced sterilization, and comparably severe acts.
Persecution — severely stripping fundamental rights from an identifiable group on political, racial, ethnic, cultural, religious, gender, or other recognized grounds.
Enforced disappearance — arrest, detention, or abduction by or with the authorization of a state or political organization, followed by refusal to acknowledge the detention or reveal the person’s fate.
Apartheid — systematic oppression and domination by one racial group over another, carried out to maintain that regime.
Other inhumane acts — a residual category covering conduct of similar gravity that intentionally causes great suffering or serious injury to physical or mental health.

That final category is deliberately open-ended. International courts have used it to prosecute forced marriage in cases arising from Sierra Leone, Cambodia, and Uganda, as well as forced mutilation and compelling family members to witness the killing of their relatives. Drafters included it because no list could anticipate every form of cruelty a regime might invent.

How This Differs From Genocide and War Crimes

The three categories overlap, and people often use the terms interchangeably, but they are distinct. Genocide requires a specific intent to destroy, in whole or in part, a national, ethnic, racial, or religious group. A crime against humanity has no such group-identity requirement; any civilian population can be the target. War crimes require an armed conflict. A crime against humanity does not — it can be committed in peacetime, which is why it reaches governments that attack their own citizens outside any war.

Who Can Be Prosecuted

Liability reaches anyone who commits, orders, solicits, aids, or otherwise contributes to crimes against humanity. Rank is no shield. The Rome Statute explicitly removes immunity from heads of state, government ministers, members of parliament, and military commanders; no official position exempts a person from prosecution or reduces their sentence.² The principle traces back to Nuremberg, where the tribunal held that individuals who commit international crimes “cannot shelter themselves behind their official positions in order to be freed from punishment.”³

Command responsibility pulls in commanders and civilian superiors who did not personally commit any violent act. A commander can be held liable if they knew, or should have known, that subordinates were committing or about to commit these offenses and failed to take reasonable steps to prevent them or punish those responsible. This is where many of the highest-profile cases focus, because atrocities on this scale rarely happen without at least tacit approval from the top. The ICC’s arrest warrants for Sudan’s then-President Omar al-Bashir tested the limits in practice; courts that considered his claim of diplomatic immunity concluded that acts amounting to international crimes cannot be treated as legitimate official functions entitled to protection.

Where These Cases Are Heard

The International Criminal Court is the permanent court established by the Rome Statute to prosecute genocide, war crimes, crimes of aggression, and crimes against humanity. The statute entered into force on July 1, 2002, and the court can only prosecute offenses committed after that date.⁴ The ICC does not replace national courts; under the principle of complementarity, it steps in only when a country is genuinely unwilling or unable to investigate and prosecute the crimes itself.

Not every country has signed on. The United States, Russia, China, and India are among those that have not ratified the Rome Statute. The United States signed in 2000, later withdrew its signature, and enacted the American Servicemembers’ Protection Act, which prohibits U.S. government agencies from cooperating with the ICC and bars extradition of any U.S. citizen or permanent resident to the court.⁵ Non-membership does not place a country’s nationals entirely out of reach, because other routes to prosecution exist.

One of those routes is universal jurisdiction. Many countries’ national courts can prosecute crimes against humanity regardless of where the acts occurred and regardless of the nationality of the perpetrator or victims, on the theory that some offenses are grave enough that every state has an interest in holding perpetrators accountable. In 2022, a German court convicted a former Syrian intelligence official of crimes against humanity, including torture, murder, and sexual assault committed in a Damascus detention facility, and sentenced him to life in prison.⁶ The crimes happened in Syria, the defendant was Syrian, and the victims were Syrian; because he was found in Germany, German prosecutors had jurisdiction.

There is also no time limit. Article 29 of the Rome Statute states that crimes within the court’s jurisdiction are not subject to any statute of limitations.² A perpetrator can be arrested and tried decades after the acts occurred. The passage of time offers no safe harbor.

1
United Nations. Definitions of Genocide and Related Crimes
2
ICC. Rome Statute of the International Criminal Court
3
Office of the Historian. The Nuremberg Trial and the Tokyo War Crimes Trials (1945-1948)
4
United Nations Treaty Collection. Rome Statute of the International Criminal Court
5
Office of the Law Revision Counsel. 22 USC Chapter 81 Subchapter II – American Servicemembers Protection
6
OHCHR Seoul. What is Universal Jurisdiction