A 14-year-old boy has been charged in the fatal shooting of his 9-year-old brother inside the family’s home in Mattapan today, prosecutors said this afternoon.
The youth, whose name was not released because of his age, is to be arraigned next week on charges of delinquency by reason of involuntary manslaughter and unlawful possession of a firearm, Suffolk District Attorney Daniel F. Conley’s office said.
Investigators believe the older boy was handling the firearm “recklessly” when it fired, hitting his younger brother, prosecutors said in a statement. The prosecutors said that the evidence collected so far did not suggest that anybody else knew the teenager had a gun.
Police were called to the triple-decker home on Morton Street near Estella Street at 11:37 a.m.
Boston Police Commissioner William B. Evans, choking up at times, said the two boys were home with an older sister at the time of the shooting. Their mother was not home, he said.
The younger brother, a fourth-grader at the James W. Hennigan Elementary School, was shot in the chest and was in traumatic arrest before he was rushed to Boston Medical Center. Police found the older brother on Walk Hill Street still carrying the gun, Evans said.
“Upon preliminary investigation, we believe that it was an accidental shooting, but unfortunately, we have [a young boy] dead at the scene,’’ Evans said. “It’s a terrible, terrible incident for the family involved here. ... Obviously, the mother is extremely distraught.’’
Evans said he arrived at the scene just as Boston Emergency Medical Services personnel were rushing the child to an ambulance.
“I was here when they wheeled him out, and to see a young boy, curly hair, with so much life to live ... ’’ Evans said. “Having three children myself, it just breaks your heart.”
Evans said he did not believe the older sibling was trying to escape from police when he ran from the family’s Morton Street home.
“I think he panicked here,’’ Evans said. “I think he realized the gravity of what he had done. And he was very cooperative with the officer.”
Boston Mayor Martin J. Walsh called the incident a tragedy. He urged residents who have an unwanted firearm in their homes to contact police, who will then come and remove the weapon. He said the older brother “should not be in a situation where he has access to a gun. ... There are far too many guns in our streets.”
Officials said they did not immediately know why the brothers were not in school today.
Homicide detectives responded to the scene to oversee the investigation. Evans said detectives were trying to determine whose firearm it was.
The principal of Hennigan Elementary sent a broadcast phone call to parents today, informing them that a fourth-grader had “passed away Friday morning after an incident at his home in Mattapan.” The principal said counselors were on hand Friday at the school and were expected to return Monday to meet with students who need assistance.
Neighborhood residents were horrified by the shooting and outraged that someone so young would have access to a gun.
“Why did a 14-year-old boy have a gun in the house?” asked Christine Hankins, 54. “You’re 14! It’s just so sad. Nine years old.’’
Nelson Martinez said the shooting was a tragic but inevitable result of so many guns in circulation — and the fear that pushes teenagers to buy weapons.
“The sad thing is it’s so easy to get a gun in Boston,” he said. “He didn’t have to look very hard.’’
Another neighbor, Cosandra Harrigan, 44, said in a telephone interview that there had been numerous shootings in the neighborhood in recent years, including one last summer in front of the house where today’s shooting took place.
“Last summer they had a wild party and somebody got shot in front of the same house, too, and died,’’ Harrigan said. “I’ve been here 17 years and I’ve witnessed a lot of shootings.’’
She added that she herself had lost a family member to gun violence on Morton Street.
Another neighbor, Debra Brown, said the news was devastating.
“There shouldn’t be a gun in the house with kids,’’ she said. “Why weren’t they in school? Where were the parents? It shouldn’t be this way.’’
Celia Gabadon, who is 72 years old, said the neighborhood had seen a lot of violence over the years, and that police have done what they can.
The solution is not more police, though, but must come from within the community, she said. “Police are doing a good job. We are to blame,’’ she said.
US Attorney Carmen M. Ortiz said she had spoken to Evans recently, they had discussed concerns about guns on the streets, and she had offered him any resources he may need.
“We’re always concerned when we see this,” she said. “I think we’re trying to work as a team, and trying to figure out how to do that.”
Ortiz added, however, that members of the community need to do more to track down guns in their homes, and turn them over to police.
“You have to get the message out into the community that we share a sense of responsibility,” she said. “The solution is not just law enforcement. The community has to be involved, do what they can, and cooperate with police.”
“We need to get out there in the community centers, into schools, through faith-based organizations, and get the word out there in the community that these guns continue to be dangerous, look what can occur, and you need to work with us to track them down and turn them over,” she said.
Today’s fatal incident had eerie similarities to the 2007 death of Liquarry Jefferson Jr., a first-grader who was shot to death by his 7-year-old cousin while they were playing with a gun left inside their apartment by an older relative.
Jefferson was eight years old when he was shot on June 24, 2007. He and his cousin had found a loaded 9mm handgun in the dresser drawer of an older cousin, Jayquan McConnico.
McConnico and Jefferson’s mother, Lakeisha Gadson, were both prosecuted by Suffolk District Attorney Daniel F. Conley’s office on charges of allowing an illegal weapon to fall into the hands of children.
Gadson was acquitted by a Suffolk Superior Court jury of the major charges she faced, while McConnico was sentenced to Department of Youth Services custody, which he has since completed.Milton J. Valencia, John R. Ellement and Martin Finucane of the Globe staff, and Globe correspondent Catalina Gaitan contributed to this report. Peter Schworm can be reached at firstname.lastname@example.org. Follow him on Twitter @globepete. Meghan E. Irons can be reached at email@example.com. Follow her on Twitter @meghanirons.