A federal judge ruled Thursday that prosecutors broke federal law in brokering a 2008 plea agreement for hedge-fund manager and millionaire Jeffrey Epstein.

Starting in 2005, Epstein was accused of orchestrating a sex trafficking ring and sexually assaulting dozens of minors. His plea agreement, which was sealed from the public record, distilled these accusations into two prostitution charges and arranged for Epstein to spend 13 months in a private wing of a Palm Beach county jail with six days of work release to his office each week.

In his ruling, Judge Kenneth Marra found that prosecutors—led by former Miami US Attorney, and current US Secretary of Labor, Alex Acosta—violated the federal Crime Victims’ Rights Act (CVRA) by sealing Epstein’s plea agreement so that Epstein’s victims could not see its terms or speak at his sentencing.

Marra’s opinion detailed a series of communications between the US Attorney’s office and Epstein’s legal team in which both parties agreed that the prosecution would not pursue federal charges and that the victims would not be notified. Marra noted that “[i]t was a deviation from the Government’s practice to negotiate with defense counsel about the extent of crime victim notifications.”

Marra also held that the prosecution acted contrary to the CVRA by leading the victims to believe an investigation was ongoing after it had finalized the plea agreement. According to the ruling, “the Government sent letters to the victims requesting their “patience” with the investigation even after the Government entered into the [plea agreement].”

Marra’s ruling gives prosecutors 15 days to confer with Epstein’s victims and their attorneys and negotiate a settlement, pursuant to the CVRA.

This case represents the first legal challenge to Epstein’s plea agreement after his alleged crimes were detailed by a Miami Herald exposé in November. The Department of Justice has also announced that it is opening up an investigation into Epstein’s plea deal, in response to repeated calls by Republican Senator Ben Sasse, Chairman of the Senate Judiciary Oversight Subcommittee, for further investigation.