A Biden-appointed U.S. attorney, who resigned on President Donald Trump’s first day in office, had been battling epilepsy before she passed away in her sleep, her family disclosed this week.

Jessica Aber, 43, formerly the top prosecutor in Virginia’s Eastern District, was found unresponsive at her Washington, D.C. home on Saturday. Police indicated that she most likely died of natural causes, noting that she had “a longstanding medical issue,” according to DailyMail.com.

Aber’s case will remain open until the Office of the Chief Medical Examiner of Virginia determines the manner and cause of her death.

Meanwhile, her family told ABC News that she had suffered from epilepsy and epileptic seizures for many years. According to the Centers for Disease Control, this condition can lead to fatal asphyxiation or heart issues.

Although fatal epileptic seizures—referred to as Sudden Unexpected Death in Epilepsy—are rare, they pose a significant risk for individuals with the disorder, often occurring while the victims are asleep, as was the case with Aber.

In a statement, Aber’s family said they “expect more information from the medical examiner in the coming weeks.”

“Our family is in shock and grieving deeply, and we respectfully request privacy as we attempt to navigate through our unspeakable loss,” the family added in a statement.

Former colleagues are also trying to cope with the sudden, tragic loss.

“Jess was brilliant, but far more important was her sense for justice, her humanity, and her ability to change the world in a positive way even during her brief time with us,” said US District Judge M. Hannah Lauck, for whom Aber once clerked.

“My clerk family has lost its rock, and I have lost a friend. She was a good soul and I am proud to have known her,” Lauck added, per the DailyMail.com.

“She was unmatched as a leader, mentor, and prosecutor,” Aber’s interim successor, Erik S. Siebert, added. “She is simply irreplaceable as a human being. We remain in awe of how much she accomplished in her all too brief time in this world. She loved EDVA and EDVA loved her back.”

Aber advanced through the ranks of the Justice Department before former President Joe Biden appointed her as the U.S. Attorney for the Eastern District of Virginia (EDVA) in 2021, making her one of the few women ever to lead the department.

According to the New York Post, Aber “had been in charge of some of the biggest cases targeting leaks in the CIA and Russian nationals carrying out fraud in America” during her tenure at EDVA.

Before stepping down in January, Aber secured one of her most high-profile courtroom victories when former CIA analyst Asif Rahman, 34, pleaded guilty to leaking top-secret documents detailing Israel’s plan to strike Iran last year.

The high-profile case involved Rahman posting classified documents on Telegram that revealed details of Israel’s planned October strike, ultimately forcing the Israeli government to delay its retaliatory attack on Tehran.

Aber shredded Rahman’s actions as a “violation of his oath, his responsibility, and the law,” as she said the leak “placed lives at risk, undermined U.S. foreign relations, and compromised our ability to collect vital intelligence in the future.”

Aber also led the prosecution against Eleview International Inc., a Virginia-based company whose two top executives were accused of orchestrating “three separate schemes to illegally transship sensitive U.S. technology to Russia,” according to the Department of Justice.

In November, executives Oleg Nayandin, 54, and Vitaliy Borisenko, 39, were charged with illegally exporting over $6 million worth of goods—including telecommunications equipment—to Russia. Prosecutors say the shipments were routed through ports in Turkey, Finland, and Kazakhstan to circumvent U.S. sanctions imposed on Moscow following its invasion of Ukraine, The Post reported.