International Atrocity Crimes and Their Domestic Counterparts
Legal Sidebari
International Atrocity Crimes and Their
Domestic Counterparts
Updated April 3, 2024
Russia’s war launched against Ukraine on February 24, 2022, the October 7, 2023, attacks perpetrated by
Hamas in Israel, and Israel’s subsequent campaign in Gaza have prompted widespread attention to the
legal framework that addresses atrocity crimes. The term atrocity crimes was coined by former U.S.
Ambassador at Large for War Crimes Issues David J. Scheffer to describe criminal conduct that is, among
other elements, “of a significant magnitude,” prohibited under conventional international criminal law,
and “led, in its execution, by a ruling or otherwise powerful elite in society.” The United Nations has
defined atrocity crimes as genocide, crimes against humanity, and war crimes. International law also
criminalizes conduct related to these crimes, such as torture and the crime of aggression. Some, but not
all, of these criminal offenses have counterparts in the U.S. Criminal Code. The Human Rights and
Special Prosecution Section in the Department of Justice (DOJ) is responsible for investigating and
prosecuting atrocity crimes and related offenses under U.S. law. This Sidebar describes international
atrocity crimes and related offenses, examines their domestic counterparts, and discusses considerations
for Congress.
Atrocity Crimes and Related Offenses That Have a
Domestic Counterpart
Genocide
The 1948 Convention on the Prevention and Punishment of the Crime of Genocide (Genocide
Convention) recognizes genocide as a “crime under international law” and obligates state parties “to
prevent and punish” it. The Genocide Convention defines the offense of genocide as the committing of
certain acts “with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as
such.” The acts that qualify for purposes of establishing genocide are (1) killing members of the targeted
group; (2) causing serious bodily or mental harm to the group’s members; (3) subjecting the group to
conditions of life intended to cause the group’s physical destruction; (4) imposing measures intended to
prevent births within the group; or (5) forcibly transferring children of the group. The International Court
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of Justice has concluded that the genocide prohibition is part of customary international law and thus
binding on all states regardless of whether they are parties to the Genocide Convention.
The United States ratified the Genocide Convention in 1988 and passed legislation implementing the
treaty into U.S. law the same year. Codified in 18 U.S.C. § 1091, the Genocide Convention
Implementation Act contains the two essential elements to establish genocide—a specific mental state and
an act—and draws on, but does not completely track, the language of the Genocide Convention. As
originally enacted, Section 1091 provided jurisdiction only if the offense was committed within the
United States or the offender was a U.S. national. In 2007, Congress passed an amendment to Section
1091 to, as stated in the House Report, “strengthen[] the ability of the United States to prosecute
perpetrators of genocide by . . . establish[ing] Federal criminal jurisdiction over the crime of genocide,
wherever the crime is committed.” As a result of this amendment, Section 1091 now provides one of the
broadest forms of extraterritorial jurisdiction in U.S. law. Federal courts have jurisdiction if the offense
was committed in whole or in part in the United States and, regardless of where the offense was
committed, if the offender is a U.S. national, a lawful permanent resident, a stateless person with a
habitual residence in the United States, or is present in the United States.
Despite this broad exterritorial application, Section 1091 does not provide “pure” universal jurisdiction,
which would permit a U.S. court to try any perpetrator of genocide. The statute requires at least some
connection between the United States and either the offender, victim, or offense. At a minimum, the
offender must be “present in the United States” (i.e., located on U.S. territory) for U.S. courts to exercise
jurisdiction over a defendant. In some circumstances such jurisdiction could also be acquired through
extradition. Several treaties prohibiting atrocity crimes—including the Genocide Convention (in Article
VII)—permit or require the extradition of persons who are not prosecuted by the country where they are
found. (Legal considerations that might inform the federal government’s ability to extradite an offender to
or from the United States are discussed in CRS Report 98-958.)
While the executive branch has concluded that certain events overseas constituted genocide, to date it has
not prosecuted anyone under the genocide statute. Although some private litigants have attempted to bring
cases alleging claims under Section 1091, courts have rejected them, recognizing that Section 1092
expressly provides that the Genocide Convention Implementation Act does not “creat[e] any substantive
or procedural right enforceable by” private parties in civil actions. Courts have, however, referenced the
definitions of genocide in Section 1091 as well as in the Genocide Convention in determining that
plaintiffs may seek civil redress under the Alien Tort Statute (ATS) (discussed in CRS Report R44947) for
alleged violations of the genocide prohibition recognized as customary international law.
In November 2023, several Palestinian groups, Gaza residents, and U.S. persons filed a suit, in part based
on ATS jurisdiction, against the Biden Administration alleging that it is violating its obligations under
customary international law to prevent genocide against Palestinians in Gaza and is complicit in genocide
by providing support to Israel for its military campaign. In response, DOJ argued that the court is without
jurisdiction to hear the claims on various grounds, including that the case raises a nonjusticiable political
question, that there is no private right of action under international customary international law or the
Genocide Convention Implementation Act, and that ATS claims may not be brought against the United
States. The district court agreed with the government that the case was nonjusticiable under the political
question doctrine and dismissed it on that ground. The court also noted, however, that it agreed with the
finding of the International Court of Justice in its January 26, 2024, order in the case South Africa v. Israel
that it was “plausible” that Israel was in violation of the Genocide Convention. For that reason, the district
court stated that it “implores Defendants to examine the results of their unflagging support of the military
siege against the Palestinians in Gaza.” The U.S. Court of Appeals for the Ninth Circuit subsequently
granted the plaintiffs’ motion for an expedited appeal and scheduled it for consideration in June of 2024.
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War Crimes
“Grave breaches” of the four Geneva Conventions of 1949 and violations of other treaties governing the
conduct of armed conflict are among the war crimes recognized under international law. The War Crimes
Act of 1996, codified in 18 U.S.C. § 2441, criminalizes these offenses under U.S. domestic law. The
background, scope, and definition of war crimes are discussed in greater detail in this CRS Legal Sidebar.
As originally enacted, the War Crimes Act provided jurisdiction for offenses “whether inside or outside
the United States,” but only if the victim or perpetrator was a U.S. national or member of the U.S. Armed
Forces. In 2023, President Biden signed into law the Justice for Victims of War Crimes Act, which
amended the War Crimes Act to provide for the same more expansive jurisdictional basis conferred by the
Genocide Act. Thus, the War Crimes Act’s jurisdiction now also extends to offenses committed
by anyone found on U.S. territory—regardless of the accused’s or the victim’s nationality.
In December 2023, DOJ brought an indictment against four members of the Russian armed forces or
allied military units for violations of the War Crimes Act—the first in almost three decades of the Act’s
existence. The indictment alleges that the four defendants perpetrated grave breaches of the Fourth
Geneva Convention against a U.S. national who at the time was living in a southern Ukrainian oblast (or
province). The Attorney General stated that this prosecution was the first of its type and that more
indictments may be forthcoming. He also suggested that DOJ’s work may not be limited to Ukraine,
stating that “Hamas murdered 30 Americans and kidnapped more” and that DOJ is “investigating those
heinous crimes and will hold those people accountable.”
Torture
The United States ratified the Convention Against Torture and Other Forms of Cruel, Inhuman or
Degrading Treatment or Punishment in 1994 and passed implementing legislation the same year that
made torture a criminal offense. The implementing legislation (18 U.S.C. §§ 2340-2340B) defines torture
as “an act committed by a person acting under the color of law specifically intended to inflict severe
physical or mental pain or suffering (other than pain or suffering incidental to lawful sanctions) upon
another person within his custody or physical control.” As currently written, the law criminalizes torture
only if the offender commits or attempts to commit the offense outside the United States, and U.S. courts
have jurisdiction if the offender is a U.S. national or is “present in the United States.”
To date, there have been two convictions under the torture statute. First, in 2008, Roy Belfast Jr., the son
of former Liberian President Charles Taylor, was convicted for his role in the torture of people in Liberia
between 1999 and 2003. Belfast, who was born in the United States, was sentenced to 97 years in prison.
Second, in 2023, a federal jury in Pennsylvania convicted Ross Roggio, a U.S. citizen who managed an
illegal weapons factory project in the Kurdistan region of Iraq, for the torture of an Estonian citizen
employed at the factory who raised concerns about the project.
DOJ has also brought torture charges in at least two other cases. In 2012, a grand jury indicted then-New
York resident Sulejman Mujagic for alleged torture in Bosnia during the armed conflict after the breakup
of the former Yugoslavia. The United States later extradited Mujagic to Bosnia so that he could be tried
for a broader set of crimes than were available under U.S. law in a forum that was closer to the victim,
witnesses, and location of the offenses. At least one other prosecution with torture indictments is still
pending. In 2020, a grand jury indicted a Gambian national residing in Colorado for alleged torture as part
of an effort to secure confessions from individuals suspected of plotting a coup to overthrow the Gambian
government.
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Atrocity Crimes and Related Offenses That Do Not Have
a Domestic Counterpart
Crimes Against Humanity
Crimes against humanity is a category of crimes that is often traced to charters of the post-World War II
military tribunals at Nuremberg and Tokyo. Since World War II, the offense has been included in the
jurisdictional instruments for several international criminal tribunals, including in the Rome Statute for
the International Criminal Court (ICC). (The United States is not a party to the Rome Statute.) Although
there is not currently a treaty dedicated to the prevention and punishment of crimes against humanity as
there is for genocide and war crimes, in November 2022 the U.N. General Assembly’s legal committee
passed a resolution launching negotiations on draft articles of a crimes against humanity treaty. The
United States was among the countries that supported the launch of the negotiations, which are currently
under way and are expected to run through the end of 2024.
Unlike war crimes, crimes against humanity and genocide may be committed during peacetime as well as
armed conflicts. Many of the same acts that can amount to genocide can also amount to crimes against
humanity, including murder, enslavement, rape, torture, and forcible population transfers. However, the
mental state required to establish crimes against humanity differs from that required to establish genocide.
While the genocide offense requires the intent to destroy a national, ethnic, racial, or religious group,
crimes against humanity require knowledge that the prohibited act was part of a widespread and
systematic attack on a civilian population. These differing mental-state standards mean that many acts of
genocide also qualify as crimes against humanity, but not every crime against humanity amounts to
genocide.
Under certain circumstances acts amounting to crimes against humanity could be prosecuted under
existing U.S. criminal statutes, including the War Crimes Act and the torture statute. U.S. criminal law
does not punish crimes against humanity per se. Several U.S. laws, however, reference crimes against
humanity in other contexts, including limitations on foreign security assistance; support for other
countries’ and the International Criminal Court’s efforts to investigate and prosecute crimes against
humanity perpetrated by foreign nationals; and a directive to the executive to develop a “Government-
wide strategy to identify, prevent, and respond to the risk of atrocities,” including crimes against
humanity. Additionally, over the years, the executive branch has determined that certain overseas
atrocities rise to the level of crimes against humanity, including in the context of the current Russia-
Ukraine conflict.
Aggression
The crime of aggression, in its broadest sense, is the act of starting an armed conflict that is prohibited
under international law. The crime was defined and prosecuted in the post-World War II military
tribunals, where it was referred to as “crimes against peace.” The Nuremberg Military Tribunal described
aggression as “the supreme international crime differing only from other war crimes in that it contains
within itself the accumulated evil of the whole.” The modern definition is reflected in Article 8 bis of the
Rome Statute, which defines the crime as the
planning, preparation, initiation, or execution, by a person in a position effectively to exercise
control over or to direct the political or military action of a State, of an act of aggression which, by
its character, gravity, and scale, constitutes a manifest violation of the Charter of the United Nations.
One component of the crime is an “act of aggression,” which the Rome Statute defines as a country’s use
of armed forces against the sovereignty, territorial integrity, or political independence of another country.
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Examples of acts of aggression include invasions, armed attacks, bombardments, blockades, and military
occupations. The ICC’s jurisdiction is more limited for aggression than for the other three crimes defined
in the Rome Statute—namely, genocide, crimes against humanity, and war crimes. For these latter three
crimes, the ICC has jurisdiction if they were committed by a national of or on the territory of a state party
or a nonstate party that has accepted the court’s jurisdiction. In contrast, the ICC does not have
jurisdiction over the crime of aggression if it was committed by a national of a state party that has opted
out of such jurisdiction or by the national of or on the territory of a nonstate party.
The ICC has jurisdiction to investigate crimes against humanity and war crimes by Russian nationals on
Ukrainian territory because Ukraine has accepted the court’s jurisdiction for that purpose. Because Russia
is not a party to the Rome Statute, however, the ICC does not possess the power to investigate allegations
of aggression committed by Russian nationals, and for this reason Ukraine may not also recognize the
ICC’s jurisdiction to investigate the commission of the crime of aggression by Russian nationals against
Ukrainians in Ukraine. Aggression is not a defined offense in U.S. law, but some foreign countries have
enacted legislation criminalizing the offense, including Ukraine.
Considerations for Congress
As the statutes permitting domestic enforcement of international legal prohibitions of atrocity and related
crimes discussed above indicate, over time Congress has periodically shown interest in avenues for
accountability. Recent conflicts throughout the world—including in Burma, Yemen, Ethiopia, Sudan,
Ukraine, Israel, and Gaza—appear to have prompted increased congressional attention to alleged
international atrocities and related crimes.
Further, as noted, DOJ has indicated that it intends to pursue additional prosecutions to hold individuals
accountable for war crimes and other atrocities. The first prosecution under the War Crimes Act was
brought by DOJ’s War Crimes Accountability Team, which the Attorney General established four months
after Russia invaded Ukraine to “strengthen and centralize the Department’s ongoing work to hold
accountable those who have committed war crimes and other atrocities in Ukraine.” Although the bulk of
future prosecutions related to Ukraine and the Israeli and Hamas conflict will likely take place outside the
U.S. judicial system, the recent amendment of the War Crimes Act extends criminal jurisdiction to
covered offenses committed by anyone found on U.S. soil, potentially enabling U.S. authorities to more
easily hold more war crimes perpetrators accountable in U.S. courts.
DOJ’s ability to prosecute other atrocities and related crimes is more limited, however. Although the
torture statute’s jurisdictional provisions are keyed to the offender’s nationality or presence, the statute
does not provide jurisdiction based on the victim’s status as a U.S. national. The absence of victim-based
jurisdiction means that the torture statute would not automatically provide jurisdiction if a U.S. national
were, for example, captured in Ukraine and tortured by Russian forces (as alleged in DOJ’s first
indictment under the War Crimes Act) or held hostage and tortured by Hamas militants in Gaza. In such
cases, DOJ would have jurisdiction only if the offender were present in the United States (although, as
discussed above, it is possible that in some cases such jurisdiction could be secured through extradition,
or the United States might opt to extradite persons under its jurisdiction to another country to face
criminal charges).
Federal prosecutors also do not have the option to bring charges for crimes against humanity or the crime
of aggression. Some observers and Members of Congress view the absence of a crimes against humanity
offense in U.S. law as a “gap” that Congress should fill by defining a new offense that captures the unique
nature of this crime. Others contend that a crimes against humanity statute risks being overbroad and
exposing U.S. military personnel to prosecution. Aggression is less frequently discussed in the context of
domestic law because of obstacles to prosecution presented by immunities afforded to state officials under
international law, but the potential role of domestic systems in enforcing the crime has received attention
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from international legal commentators because of the restrictions in the Rome Statute preventing the ICC
from exercising jurisdiction over Russian nationals for this crime.
When prosecution is not an option under the set of federal atrocity-related crimes, DOJ can still use
common criminal charges (e.g., murder and other violent crimes) to address individual acts that formed
part of a widespread atrocity campaign. Other options U.S. authorities can use are immigration laws to
remove or denaturalize aliens accused of atrocity crimes by prosecuting them for making false statements
or for committing fraud either during the immigration process or on immigration forms. Some observers
have questioned whether atrocity crime reform is necessary when the United States can leverage existing
criminal and immigration laws to target offenders. Being charged with traditional criminal and
immigration offenses, however, may lack the defining features and stigma of being prosecuted for atrocity
crimes, and they may have shorter statutes of limitation or restrictions on exterritorial reach. At the same
time, it is not clear that adding new offenses or expanding jurisdiction for atrocity and related crimes
would result in many new convictions; the United States to date has two convictions under its suite of
atrocity-related criminal statutes—the 2008 and 2023 torture convictions. On the other hand, it is possible
that this could change in light of developments such as Congress’s recent amendment of the War Crimes
Act to expand its jurisdiction and DOJ’s recent indictment under the Act and stated commitment to further
pursue accountability in Ukraine and beyond.
Author Information
Stephen P. Mulligan
Karen Sokol
Legislative Attorney
Legislative Attorney
Disclaimer
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