Following the rout of the Islamic State of Iraq and the Levant (ISIL) in and around Raqqa, hundreds of ISIL fighters are now in the custody of US-backed opposition groups such as the Syrian Democratic Forces (SDF) and the Free Syrian Army. These groups do not have the capacity to undertake long-term detention operations in compliance with international humanitarian law. Many of those detained are foreign fighters, who hail from outside the region and from U.S. allies. During a meeting in Rome this week, Secretary of Defense Jim Mattis is expected to urge members of the anti-ISIL coalition to take back their nationals to determine the best course of action. According to a Pentagon spokeswoman:

We are working with the coalition [against Isis] on foreign fighter detainees, and generally expect these detainees to return to their country of origin.

That may be an appropriate disposition for many of these foreign fighters.  However, there are two such combatants in SDF control—El Shafee Elsheikh and Alexanda Amon Kotey—who can, and should, be prosecuted here in the United States in federal courts.

Elsheikh and Kotey are members of a group of British jihadis dubbed “The Beatles.” The two men are linked to the British terrorist Mohammed Emwazi (a.k.a. “Jihadi John”), who was killed in a 2016 air strike, and have been stripped of their citizenship. The two are believed to have been involved in the 2014 beheadings of at least three U.S. citizens—Journalists James Foley and Steven Sotloff and aid worker and former Army Ranger Peter Kassig—as well as the deaths and mistreatment of multiple other ISIL hostages. All three beheadings were gruesomely captured on trophy videos in which the journalists appear in orange jumpsuits reminiscent of early Guantanamo photographs. US personnel have apparently already interrogated the two men and confirmed their identities. The mother of James Foley has urged the prosecution of her son’s killers.

Mrs. Foley’s poignant request could be granted. The United States has the necessary legal framework in place to prosecute both captured men for these murders in federal court. As I’ve written previously, the murder of war correspondents is a war crime punishable under U.S. law. Although the U.S. War Crimes Act does not go as far as it could under international law, it does give U.S. courts clear jurisdiction over war crimes committed by or against U.S. citizens. Included in the list of war crimes is hostage-taking and the murder of a civilian taking no active part in hostilities, a crime subject to the death penalty.

The United States has never activated this statute—the brutal murders of Foley, Sotloff, and Kassig offer an opportunity to rectify this. As I noted in my earlier post on these depraved killings, gaining physical custody of the accused often proves to be the real challenge when it comes to war crimes trials. With Elsheikh and Kotey in the hands of our allies on the ground, that impediment is now removed.

Furthermore, if these two can be linked to the videotapes of these deaths or identified by former hostages, such as French journalist Nicholas Henin, the Department of Justice will have direct evidence of their complicity in the deaths of U.S. citizens. As such, this is not the case of a battlefield capture of anonymous fighters with no direct evidence of their involvement in war crimes.

In any case, if the prospect of a war crimes prosecution is too daunting for the DOJ, the federal penal code also allows for the prosecution of the murder of any U.S. citizen abroad. Plus, we have the material support statutes and a statute criminalizing the receipt of military training from designated terrorist groups. (See my coverage of these statutes and their contemporary application to U.S. citizens here).

We have already taken custody of one U.S. citizen-foreign fighter “John Doe” (see our coverage here and here and here), although his fate remains uncertain and subject to litigation by the American Civil Liberties Union (ACLU). Notwithstanding the statutes I identify above—there still seems to be some question about what John Doe can be prosecuted with given the evidence on hand.

In other related news, the Center for Justice & Accountability (an organization with which I am affiliated) has sued the nation of Syria under the Foreign Sovereign Immunity Act for the assassination of war correspondent Marie Colvin during the siege of Homs.  A U.S. district court has certified that the Syrian government was properly served on February 15, 2017.

These civil suits are important, but they are no substitute for robust criminal accountability. The United States should prosecute individuals who kill U.S. citizens to the full extent of U.S. law.

(Gokhan Sahin/Getty Images)