With Suffolk County District Attorney Rachael Rollins set to be sworn in as U.S. Attorney on Monday, Gov. Charlie Baker has made his selection for who will succeed her as the chief prosecutor for Boston, Chelsea, Revere and Winthrop, possibly setting up a race for an open seat later this year.

Baker picked Sex Offender Registry Board Chairman Kevin Hayden as interim district attorney. He will serve the remainder of Rollins' term, which expires in 2023.

When filling interim slots like this, Baker has frequently picked individuals uninterested in running for their own term, though Hayden could still decide to become a candidate. A press release announcing Hayden as Baker's pick did not specify whether Hayden had committed to staying out of the race in 2022.

Baker appointed interim Suffolk DA John Pappas in 2018 after elected DA Dan Conley resigned to take a job in the private sector. Pappas did not seek reelection that year, paving the way for a competitive Democratic Party primary race, which Rollins won.

Before joining the Sex Offender Registry Board in 2013, Hayden, a Black man, spent more than 10 years with the Suffolk district attorney's office as a prosecutor attached to the gang unit, safe neighbor program, juvenile court and other units.

An open district attorney seat in Suffolk County could turn into a high-profile race to succeed Rollins, who was the first woman and first woman of color elected to serve as the county's top prosecutor. Essex County District Attorney Jonathan Blodgett and Cape and Islands DA Michael O'Keefe both announced this week that they will not seek reelection.

Three open DA races around the state could have an impact on the political tenor of Massachusetts in 2022 as the nation continues to debate the roles of police and prosecutors in society, and as Democrats vie to retake the governor's office.