Rahsaan Hall wanted people to know what a district attorney does. Now he’s running for Plymouth DA.

Rahsaan HallCraig F. Walker/Globe Staff/file

Five years after Rahsaan Hall led an effort to inform Massachusetts residents about the power and influence of district attorneys, the lawyer and civil rights activist is launching a different kind of campaign.

Hall, a 49-year-old former Massachusetts ACLU official, said Tuesday he is running for Plymouth district attorney, promising reform and accountability from an office that has been occupied by the same prosecutor for two decades.

“My vision requires us to reclaim the spirit of justice as something more than tough-on-crime rhetoric, or law-and-order politics and posturing, but rather integrity and accountability,” he said Tuesday at a restaurant in Brockton.

The Brockton Democrat is a former assistant district attorney and former director of the racial justice program for the ACLU of Massachusetts. He is running for the Democratic nomination and, should he win it, would face longtime Plymouth District Attorney Timothy Cruz, a Republican who has held the position since 2001 and never faced a GOP primary challenge.

Cruz, who has been endorsed by Governor Charlie Baker and a long list of law enforcement groups in the past, won 57 percent of the general election vote in 2018 and ran unopposed in 2014.

In an e-mail, Cruz wrote that he is “committed to this job.”

“I welcome Rahsaan Hall to Plymouth County, where I have been at work for years protecting the public safety, that of our seniors and victims of sexual assault and child abuse,” he said. “We are on the right path in Plymouth County.”

Plymouth County District Attorney Timothy Cruz spoke to media in 2014. He is running for reelection for the office he has held since 2001.george rizer

Hall is a first-time candidate but has a long history in politics. In 2020, he helped lobby for a police reform bill and in 2017, directed the What a Difference a DA Makes campaign for the ACLU, which was meant to help residents understand the role of a district attorney.

“That work revealed how little people really knew about one of the most powerful individuals in the criminal legal system — the district attorney,” he said in his announcement speech.

He was joined by Geraldine Hines, a former associate justice of the Massachusetts Supreme Judicial Court, state Representative Michelle Dubois, and community activist Bri Nichols.

“We deserve a change,” Dubois, a Brockton Democrat, said.

Before Hall joined the ACLU and Lawyers for Civil Rights, he worked as an assistant district attorney in Suffolk County, where he prosecuted drug, gang, and homicide cases.

He is a graduate of Ohio State University and Northeastern University School of Law, and is an ordained reverend in the African Methodist Episcopal Church.