A Dorchester activist who has lost two sons to violence issued an emotional plea for peace Thursday, after tragedy struck again when her nephew was fatally shot the night before on his birthday.

“I want to tell the young people not to lose hope,” said Isaura Mendes, 62, a longtime peace activist, in a phone interview. “I want them to be strong, and just to be OK, and be at peace with one another.”

Mendes identified the victim in Wednesday night’s shooting outside 26 Albion St. in Dorchester as her nephew, Leroy Carvalho, a father of a young son. Friends said he was 31.

Advertisement - Continue Reading Below

He was standing outside his home and getting ready to celebrate his birthday when he was gunned down shortly after 10:15 p.m., Mendes said. She added that Carvalho’s girlfriend is grieving after the shooting and that the ordeal may ultimately “destroy her.”

“She needs help,” Mendes said. “I guess we all need help, all of the survivors, the people who live with this tragedy every day.”

Mendes and her family have endured a wave of tragic losses dating back more than two decades. One of her sons, Bobby, was stabbed to death in 1995 in Dorchester at the age of 23. Another son, Alex, 24, was fatally shot in 2006 near the location of his older brother’s murder.

And in a further family tragedy, Carvalho himself had previously lost two brothers, Luis and Christopher, to shootings in the early 2000s. Mendes said she has lost yet another nephew, though she did not discuss details of his death.

“It’s very painful,” Mendes said. “I don’t know why they are getting killed. I don’t know why people are doing it. ”

David Estrada, a Boston police spokesman, said Thursday that there was no information on a possible motive for Wednesday’s shooting. No arrests have been made.

Mendes is the co-founder of an annual march for peace that was established in 2000. She has regularly expressed a message of forgiveness at the event and reiterated that call on Thursday, urging young people involved in conflicts to avoid resorting to violence.

“If they are in pain, [I] ask them not to hurt one another,” she said. “This stuff is really killing us. We need to live with one another in peace, and I’m begging them not to get revenge, because we cannot take this anymore.”

Also Thursday evening, volunteers organized a gathering in Carvalho’s honor in front of the Boston police station in Roxbury. Attendees were calling for “an end to gun violence in our communities,” according to a press release from organizers.

Among the crowd, which grew to about 40 people, was state Representative Carlos Henriquez, of Dorchester, who said he and Carvalho were close friends.

“Leroy was a guy who brought happiness to people,” Henriquez said. “Always in a good mood, always joking.”

An event organizer, Joao Depina, 34, of Roxbury, lamented the most recent loss suffered by Carvalho’s family.

“It’s unfortunate that there’s somebody in our community with so much hate in his heart, that he would take away a mother’s child,” Depina said.

Carvalho’s slaying was the 37th homicide in Boston this year, compared to 39 at the same time in 2012, according to police statistics. Anyone with information about the case can call homicide detectives at 617-343-4470 or the department’s anonymous tipline at 1-800-494-TIPS.

The public can also send anonymous text messages to police by texting the word TIP to 27463.