U.S. Attorney Rachael Rollins’ decision to step down amid an ethics investigation shocked the city’s mayor and the two senators who recommended her for the post.

“I’m surprised at the news,” Boston Mayor Michelle Wu said at an unrelated press event on Tuesday, hours after an attorney for Rollins announced she would be submitting her letter of resignation to President Biden by the end of the week.

Wu and U.S. Sens. Ed Markey and Elizabeth Warren continued to stand firmly behind the state’s top prosecutor — despite the anticipated Wednesday release of the results of an ethics probe into her appearance at a DNC fundraiser attended by First Lady Jill Biden last year.

“Rachael Rollins has for years dedicated herself to the people of Massachusetts and equal justice under the law,” Markey and Warren said in a joint statement. “We will respect her decision.”

Biden nominated Rollins for U.S. Attorney of Massachusetts two years ago, based on a recommendation from Markey and Warren. The nod was a controversial one, splitting the Senate Judiciary Committee at the time, with Vice President Kamala Harris casting the tie-breaking vote in favor of then-Suffolk DA Rollins.

Opposing Republican senators at the time panned what they saw as Rollins’ “pro-criminal agenda,” and so-called “do-not-prosecute list,” while Democrats came to her defense, stating that her policies had “not resulted in a rise in crime,” the Herald previously reported.

Wu said she was waiting for more information to come out before providing further comment, but did say that Rollins has been “an impactful partner in Boston on a number of issues.’

“I know that she’s been a leader that’s made a difference in Boston in many, many ways,” Wu said. “There have been many spaces where, no cameras present, she was hard at work building community.”