The Justice Department filed charges Monday against the wife of a dead ISIS commander, alleging that she was part of a conspiracy that resulted in the death of Kayla Mueller, a 26-year-old American aid worker who was kidnapped by ISIS in Syria.

But the ISIS widow, known as Umm Sayyaf, is unlikely ever to see the inside of a U.S. courtroom as she is already in custody in Iraq. A U.S. official told The Daily Beast that the charges against her were more of an “insurance policy” in case Iraqi officials fail to charge her or she is ever transferred to another country or she escapes prison.

The charges also didn’t answer lingering questions about how Mueller died. The so-called Islamic State widely known as ISIS has said she was killed during a Jordanian air strike in February 2015 that meant to avenge the immolating of a Jordanian pilot held by ISIS. U.S. officials have refuted that claim but haven’t offered any alternative explanation of how Mueller died.

The charges allege that Umm Sayyaf, whose real name is Nasrin As’ad Ibrahim, knew that Mueller was being held against her will as a sex slave, along with two young Kurdish women in the home of Umm Sayyaf and her husband, known as Abu Sayyaf, who was a top ISIS official involved in its illicit oil trade.

Umm Sayyaf is in the custody of the Kurdish Regional Government in Iraq. She was captured by U.S. forces in Syria during a raid on an ISIS compound in May 2015. Her husband was killed, and she was taken into American custody and interrogated in Iraq by an American unit that operates outside the traditional criminal justice system.

But Umm Sayyaf is an Iraqi citizen, and ultimately the Obama administration deferred to Iraqi law, handing her over to authorities there. Officials told The Daily Beast at the time that they expected the Kurds to “throw the book” at her and that justice would be swift. But nine months later, there have been no reports of charges filed against Umm Sayyaf.

It was unclear if the Obama administration’s confidence in the Iraqi justice system had waned.

A Justice Department spokesman said the U.S. is still “fully committed to the Iraqis putting her through their justice system. No cards were taken off the table when she was transferred to Iraqi custody, and we have consistently said the U.S. justice system is a powerful tool to use against those who harm or kill our citizens,” Justice Department spokesman Marc Raimondi told The Daily Beast.

The idea that the U.S. always maintained the option of prosecuting Umm Sayyaf is something of a turnabout from previous statements.

The U.S. and Iraq do not have an extradition treaty. At the time Umm Sayyaf was captured, a U.S. official told The Daily Beast, “We discussed the idea of her surrender and extradition to the U.S. with senior-level [government of Iraq] officials, but ultimately that option was not available as Iraq has a constitutional prohibition on surrendering Iraqi citizens to foreign authorities.”

Because of that, Monday’s charges were meant, at least in part, as a way of ensuring that if Umm Sayyaf were freed, transferred to another country, or if she escaped, then U.S. law enforcement would be authorized to apprehend her on the conspiracy charges. The charges against her could carry a sentence of life in prison.

In an affidavit, the Justice Department also alleged that Mueller had been raped by the ISIS leader, Abu Bakr al-Baghdadi, while she was being held in the home of Umm Sayyaf and her husband. Mueller was at various times handcuffed or held in locked rooms and she was “sexually abused by Baghdadi, who forced her to have sex with him,” according to a department statement.

Mueller’s family had previously said that officials had told them Mueller was sexually abused while in ISIS custody.

Saturday marked the one-year anniversary of when Mueller’s family and U.S. officials learned of her death through a video sent to the family by her captors.

A Mueller family spokesperson told The Daily Beast that officials had told them they were filing charges against Umm Sayyaf before the charges were publicly announced.