Ricardo Arroyo, a Hyde Park city councillor whose district includes parts of Mattapan, is running for Suffolk County district attorney.

His campaign kicks off at 9:30 a.m. at the Birch Street Plaza in Roslindale.

The son of Felix D. Arroyo, the Suffolk County register of probate and a former city councillor, Ricardo Arroyo is a former public defender who worked for the Committee for Public Counsel Services.

Kevin Hayden, the former chairman of the state’s Sex Offender Registry Board, is serving as interim Suffolk DA. Gov. Charlie Baker appointed him after Rachael Rollins took the federal job of US attorney for Massachusetts. Hayden has indicated that he will make a bid for the permanent seat.

Suffolk County includes Boston, Chelsea, Revere and Winthrop.

Arroyo won re-election to the 13-member Boston City Council in 2021. He was up against challenger John White, a former laborer with Dorchester’s Local 223, and won 75 percent of the vote. Arroyo was first elected to District 5 in 2019, replacing Tim McCarthy and beating his opponent by about 700 votes.

Arroyo’s district includes Hyde Park, Readville, Roslindale and parts of Mattapan’s Ward 14 and Ward 18. Arroyo doesn’t have to give up his Council seat to run for the job, though if he wins the race for district attorney, a special election will be held to replace him in District 5.

Arroyo has $89,000 in cash on hand in his campaign account, according to the latest numbers available from the Office of Campaign and Political Finance.

His first meetings as a candidate for district attorney, according to his campaign, will be with the Dorchester-based Louis D. Brown Peace Institute, which offers help to families of homicide victims, and the Gavin House, which provides addiction recovery services.