Former MassDOT and Massport general counsel Rachael Rollins is one step closer to becoming the next Suffolk County district attorney.

Rollins beat out a field of four other Democrats vying to replace Dan Conley in the first open Suffolk County DA seat in almost 100 years.

During the campaign, Rollins emphasized her background as a woman of color who'd taken on leadership positions in state agencies while also balancing being a mother to a teenage daughter and guardian for two of her nieces.

She stressed the need for the DA's office to remember it's a service industry — and should treat its customers — victims, suspects and their families — with respect and care. That might mean checking in with the mother of a homicide victim regularly, even when there's not an update on the case.

The seat had gotten extra attention this year, as the ACLU and other advocacy organizations highlighted the power of the position over how justice is meted out in and around Boston.

The open seat drew five Democrats: Rollins, state Rep. Evandro Carvalho, former prosecutor Linda Champion, Suffolk County assistant district attorney Greg Henning, and former defense attorney and nonprofit head Shannon McAuliffe.

Rollins' election follows other reform candidates' wins across the country — including Kim Foxx in Chicago's Cook County, and Larry Krasner in Philadelphia.

Rollins will face off against Brockton defense attorney, Michael Maloney, the independent candidate, in November. No Republicans ran for the seat.