He was a “heavy hitter’’ on city streets, Kevin Sibley recalled. But, after getting stabbed at the Ashmont train station in 2014, he finally sought help.

The 24-year-old man and Sibley, a self-appointed social service advocate at the time, would meet two to three times a week. The man, known as Shongi,got a job through Building Pathways, a job training program sponsored by Action for Boston Community Development. He moved into a new apartment, along with his girlfriend and mother.

Sibley described how the man was doing so well, and then, he paused: “He was killed.’’

It is a lesson that Sibley takes with him in his new role as director of Boston’s recently created Office of Returning Citizens. Even those who are willing to seek help, Sibley says, must contend with their history.

“As we move forward in what we’re trying to do, in terms of rehabilitating our lives, we have to be very honest with ourselves about our past,’’ he said in an interview. “And if we are to move ahead successfully, we have to choose a proper path for us to do so. If we need to change our people, places, and things, that’s what we must do.’’

Roughly 3,000 federal, state, and county prison and jail inmates return to Boston each year, often with no guidance to help them find jobs and housing. Sibley is now charged with aiding that difficult transition — challenges that range from finding housing, to getting mental health and substance abuse treatment.

According to a 2014 Harvard University study that monitored more than 120 men and women released to Boston streets in one year, just over half had secured a job within 12 months. Six months out of prison, 35 percent were still staying in temporary housing.

The study also noted the burden that former inmates place on family members who agree to house them, feed them, bring them to jobs, or watch their children.

“There are a lot of ex-prisoners who are in our city, and it’s a real struggle,’’ said Lewis Finfer, executive director of the Massachusetts Communities Action Network. Finfer reiterated the need for guidance to substance abuse or mental health treatment programs, job training, and housing assistance, calling them “the cornerstones of our lives, especially for ex-prisoners.’’

“People need a lot of support to go forward in their lives,’’ he said.

Mayor Martin J. Walsh announced the creation of the Office of Returning Citizens in October.

The office has a budget of $300,000, and Sibley’s salary is about $75,000, according to public records.

The office is based in part on similar efforts in Philadelphia and Washington, D.C., which have looked at different ways to assist residents returning from prison. Philadelphia, for instance, grants tax incentives for businesses that are willing to hire former inmates.

Sibley said he sees himself as a resource to those returning to the community from prison or jail, where they may have lost any family or community they had.

They are morals, he said, he learned growing up in Dorchester as the oldest of eight children. He served in the US Army and attended the University of Massachusetts. Early in his career, he worked for a Fortune 100 company, though, he says, he never saw that as hislife plan. After he attended the Million Man March with fraternity brothers in 1995, he found a new sense of purpose as a community advocate.

“I came back with a different lens to look at what my contributions should be,’’ he said.

He joined the YMCA in Dorchester as athletic director, where he saw the needs of poor and disadvantaged youth. There, and later working with Action for Boston Community Development, he advocated for those youth — many of whom had absentee parents — by helping them navigate the judicial system following juvenile arrests, or sitting in with students in meetings with their teachers.

He saw a justice system and a school system that were failing its most in need. According to a state study on the criminal justice system that was released earlier this year, two-thirds of those who leave county jails and more than half of those who leave state prison end up back in the criminal system within three years.

“Systems were created to benefit some and disenfranchise others,’’ he said, “and as we look at this in an honest way, we have to look at what we do to contribute to the change of the system.’’

Sibley was on the “ground floor,’’ as he put it, in StreetSafe Boston, an initiative by the Boston Foundation to target at-risk youth with job training and learning programs in Boston’s most violence-prone neighborhoods.

And now, he said, he will work with a population similarly in need: adults who could not take advantage of those services, wound up in jail or prison, and are set to return to Boston’s streets — similarly in need of guidance.

“We can’t get there unless we rely on each other, and we assist each other,’’ he said.

Milton J. Valencia can be reached at milton.valencia@globe.com. Follow him on Twitter @miltonvalencia.