BOSTON (CBS/AP) — Suffolk County District Attorney Rachael Rollins, the first woman of color to serve as a D.A. in Massachusetts, was nominated Monday by President Joe Biden to become the state’s top federal prosecutor.

If confirmed by the U.S. Senate, Rollins, who has been Suffolk D.A. since 2019, would become the first Black woman to serve as U.S. attorney for Massachusetts.

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“District Attorney Rollins is a great choice for U.S. Attorney, and we were proud to recommend her to the Biden administration,” Massachusetts Senators Elizabeth Warren and Ed Markey said in a joint statement Monday.

“District Attorney Rollins is a national leader on transforming the criminal justice system and shifting away from an approach based on punishment and penalization to one that combats the root causes of injustice, whether it be poverty, substance use, or racial disparity. She has prosecutorial experience, and is dedicated and committed to advancing equal justice for all, and we are certain that she will be a tremendous U.S. Attorney. We will work to make sure she is confirmed as quickly as possible.”

Rollins said she is “incredibly humbled by the great honor” and remains focused on keeping the residents of Suffolk County safe.

Rollins defeated the district attorney candidate backed by the longtime incumbent and police groups in the 2018 Democratic primary on a promise to decline prosecution for certain low-level crimes. She argued people shouldn’t be jailed for crimes that result from mental health or addiction problems and said she wanted to focus her attention on serious crimes, like homicides.

Governor Charlie Baker says he reached out to Rollins and congratulated her Monday morning. He says he will start the process to find her replacement. “We’ve got time to figure out what to do next,” Baker said.

Acting Boston Mayor Kim Janey said, “She’s an amazing public servant and I am blessed to call her a sister in service in this work and I have nothing to offer her but my deep deep gratitude for the work that she has done already as Suffolk County District Attorney and the many great things that I know she will do in that role once she is confirmed.”

As the top prosecutor for Boston and surrounding communities, Rollins has been outspoken about the need for police reform in the wake of high-profile killings of people of color by law enforcement across the U.S. In an interview with The Associated Press in April, she said the country must do away with the misconception that questioning the police or suggesting ways they can improve means “you don’t back the blue.”

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“The police have an incredibly hard job, and believe me, I know there are violent people that harm community and police but that’s not all of us. So we have to acknowledge that it’s not working and we have to sit together to come up with solutions, but it’s urgent,” Rollins said at the time. “I’m afraid, I’m exhausted and I’m the chief law enforcement officer so imagine what other people feel like,” she said.

Rollins has also sparred with Boston’s largest police union, which accused her last summer of inciting violence against law enforcement after she tweeted: “We are being murdered at will by the police … No more words. Demand action.” Rollins rebuffed the union’s criticism, saying on Twitter, “White fragility is real people.”

In one high-profile Boston case, she moved to overturn the remaining firearm conviction for a man who spent more than 20 years in prison for the killing of a police officer before his murder conviction was overturned. Rollins’ said the case of Sean Ellis, whose fight to prove his innocence was documented in the Netflix series “Trial 4,” was “tainted by significant and egregious police corruption and prosecutorial misconduct.”

As district attorney, Rollins has also vowed to push to end mandatory life-without-parole sentences for those who committed killings between the ages of 18 and 20. Such punishments are already outlawed for juveniles. She said in an interview with the AP last month that she would ask the state’s highest court to rule that such defendants get a special sentencing hearing to consider their youth before punishments can be handed down.

“We are going to move now to make sure that overwhelmingly Black and brown men aren’t disproportionately impacted by the criminal legal system,” Rollins told the AP. “We’re going to do what’s right and at least have them have more hope and opportunity … to believe that they can change after 10, 15, 20 or so years.”

“Rachael Rollins really demonstrated what a difference a district attorney makes,” said Carol Rose, executive director of the ACLU of Massachusetts. Rose said the ACLU does not endorse political candidates but appreciates Rollins’ innovative approach to the law.

“I would love to think that as we have this national conversation about the need for rethinking our approaches to the criminal system, that having the voice of Rachael Rollins at the table can only be a good thing,” Rose said.

Rollins, who used to work as an assistant U.S. attorney in Massachusetts, would be just the second woman to head the state’s federal prosecutors’ office. Carmen Ortiz became the first woman and the first Hispanic to serve as U.S. attorney for Massachusetts in 2009.

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(© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press’ Alanna Durkin Richer contributed to this report.)