The number of people who have rallied in the Mother’s Day Walk for Peace has skyrocketed over its 20 years. And Sunday, the walk itself more than doubled.

For nearly 7 miles, families, friends, and supporters of Boston homicide victims chanted and marched from Fields Corner in Dorchester to Roxbury, the South End, Downtown Crossing, and eventually City Hall Plaza. As the walkers wound through Dorchester and Roxbury, they were greeted by scores of neighbors, encouraging them with waves and shouts. But as they moved toward downtown Boston, many passersby said they were unfamiliar with the walk or its purpose.

This is why Tina Chery, who cofounded the event after her 15-year-old son was killed in gang crossfire, changed the route this year.

“Violence is not a Dorchester problem. Violence is not a Roxbury or Mattapan problem. It is a city problem,’’ Chery said to cheers in her opening remarks at a Fields Corner park. “We are remembering, we are commemorating, and we’re standing together in unity.’’

Once at City Hall, Chery and others spoke about the benefits of forgiveness.

During the program, Chery publicly embraced her son’s killer, who was recently paroled after decades in state prison.

In 1993, Charles Bogues fatally shot and killed Chery’s son, 15-year-old Louis Brown, who was caught in crossfire during a Dorchester shootout between rivals. Brown, who dreamed of being president of the United States, was shot near the Fields Corner MBTA station as he planned to take a train to an anti-gang meeting, according to reports from the time.

Bogues pleaded guilty in 1997 to killing Brown and was paroled in 2012. On Sunday, Bogues said he felt honored that Chery had invited him to speak, and that the two had developed an amicable relationship while he was in prison.

“I stand before you a business owner, who is a good son, father, uncle, nephew, and friend,’’ Bogues told the marchers. “You can make a difference in your own life.’’

His message was well-received by the crowd, which was sprinkled with relatives of slain Bostonians from years past and present. Some families, like those of Antoine Marquis Dingle-Knight of Dorchester, Warren Hairston of Roxbury, and 13-year-old Steven Odom of Dorchester, have marched in the peace walk for years. Others made T-shirts and posters bearing the images of those recently slain, such as Jephthe Chery of Mattapan, and 3-year-old Kenai Whyte of Roxbury.

Nyarie Bacchus, an eighth-grader, walked for her father and for her aunt, who were murdered four years apart on the same South End corner.

“It makes me angry every year, when I see new and different faces on a poster,’’ said Audrey McKenzie, a woman from Dorchester.

McKenzie’s son, Damaine Brown, was shot and killed in 2005 during crossfire on Blue Hill Avenue. On Sunday, she marched in the peace walk with her daughter, 9-year-old Deandra, who was never able to meet her brother.

“I don’t want to be here, but I have to be,’’ McKenzie said.

Her tone captured an emotional day with an atmosphere at times festive, then somber as a funeral. Many walkers, which included Boston Mayor Martin J. Walsh, former Massachusetts governor Deval Patrick, and Attorney General Maura Healey, paraded joyfully through the streets as pop songs blared in the background. At other times, quartets played gospel spirituals next to posters of murdered men and women, like Anthony Smalls of Dorchester, and Derek Matulina of Boston.

Marva Hylton, who marched for her grandson, 22-year-old Raheem Ramirez, wept as she walked.

Ramirez was fatally shot when someone fired into a crowded Roxbury corner last July, just one week before he completed the city’s job-training program.

Sunday marked Hylton’s first Mother’s Day without him.

“I look at his picture, and I still can’t believe he’s not with us,’’ Hylton said as she dabbed her eyes.

Walsh, who served as one of the event’s honorary cochairs, said he remembers helping to plan the inaugural peace walk in Chery’s kitchen, decades ago. In his short remarks to the crowd at Fields Corner, Walsh cited crime statistics that show homicides have decreased 54 percent since 1996. He also said there’s “still more work to do.’’

According to Tina Chery, 1,296 people have been murdered in Boston since her son died in 1993 — one life lost every six days.

Astead W. Herndon can be reached at astead.herndon@globe.com.