Massachusetts U.S. Attorney Rachael Rollins hired former Justice Department Inspector General Michael Bromwich to represent her in a widening ethics investigation into her appearance at a political fundraiser and travel. The department’s current inspector general, Michael Horowitz, launched the investigation after Rollins’ July appearance at a Democratic National Committee fundraiser. The probe has broadened to examine her travel and cellphone use for official business.

Rollins is a proponent of the “progressive prosecutor” movement that supports eliminating racial disparities in the justice system. She is the first Black woman to serve as the top federal prosecutor in Massachusetts. The controversy has threatened to undermine Attorney General Merrick Garland’s vow to protect the Justice Department from partisan influence and efforts to extend progressive Criminal Justice Policies championed by Rollins to the federal level.

The investigation began at the urging of Republican Senator Tom Cotton after the Boston Herald photographed Rollins arriving in a government vehicle at a house in Andover, Massachusetts, where a DNC fundraiser was being held with First Lady Jill Biden. Following the event, Garland issued a memo banning political appointees including Rollins and the other 92 U.S. Attorneys from attending campaign events or fundraisers. Previously, they had been permitted to attend in their capacities with department approval.

The U.S. Office of Special Counsel, an independent government watchdog, launched a parallel probe in August to investigate whether Rollins violated the Hatch Act, which restricts political activity by federal government employees.

Investigators are also looking into a June 2022 trip Rollins took to California to speak on a panel at CAA Amplify, an annual business summit run by the Hollywood talent agency Creative Artists. Rollins’ travel was paid for by the group, violating Justice Department policy, and she later had to repay the organization.

The probe is also investigating the leak to the Boston Herald newspaper of a Justice Department memo about Rollins’ recusal from an investigation of Kevin Hayden, Rollins’ successor as the Suffolk County district attorney, who faced a challenge from a progressive police reform advocate during last year’s elections. The identity of the source of the leak remains unknown. Hayden has not been charged and denies wrongdoing.

Investigators are also looking at Rollins’ use of a personal cellphone, rather than her government-issued one, for Justice Department business.

It is still being determined what the inspector general’s probe will find or when it will be completed. Rollins has publicly acknowledged the probe in the past, stating that her “only regret” was that she did not want the prosecutors who work for her “distracted by what is happening with respect to me.”

Bromwich previously represented former FBI Deputy Director Andrew McCabe after he was fired during the Trump administration and Christine Blasey-Ford when she went before the Senate to accuse now-Supreme Court Justice Brett Kavanaugh of sexually assaulting her in high school.

The controversy has generated significant interest due to Rollins’ position as a leading proponent of progressive criminal justice policies. Advocates and policymakers will closely watch the investigation in the field.