As 9-year-old Janmarcos Peña played video games in the den on Feb. 7, his older brother walked toward the room, holding a semiautomatic handgun. Juanly Peña would later tell police he had taken out the magazine and thought the chamber was empty.
But when he squeezed the trigger, a bullet fatally struck his little brother in the chest, piercing his heart. The elder brother was less than 3 feet away from Janmarcos when he fired.
“The child had no chance,” Assistant District Attorney Ian Polumbaum told a Boston juvenile court judge Monday morning. A not-guilty plea was entered on behalf of Juanly Peña, 14, who was held on $50,000 cash bail. It was the same amount set on Feb. 10, when he was first charged as a juvenile in the killing.
On April 18, a Suffolk grand jury indicted Peña on charges of manslaughter and unlawful possession of a firearm. A not-guilty plea was entered on his behalf.
His legal status as a youthful offender exposes him to potentially stiffer penalties and opens his case to the public.
A juvenile convicted of a crime, or found delinquent, is rarely identified and is typically sent to state custody, where he or she can be held only until age 18. A youthful offender, however, can be committed to the Division of Youth Services until age 21, receive an adult sentence, or a combination of both. The maximum sentence for manslaughter is 20 years.
Police have said they believe the shooting was accidental.
On Monday, Polumbaum was careful to stress that by charging him as a youthful offender, prosecutors were not accusing the teenager of purposely killing his brother.
“It’s not an allegation of intentional murder,” said Polumbaum. “It’s a charge of wanton and reckless conduct causing death. Our view is, when you squeeze the trigger of a gun pointed toward a child less than a yard away, that even a minor would or should know the reasonable risk of harm inherent in that conduct.”
Peña’s lawyer, Michael Doolin, declined to fight the bail amount, saying he understood the prosecution’s reasons for wanting to hold his client.
The teenager has a long history of trouble in school and with the law. At the time of the killing, Peña had stopped going to classes, though he was enrolled at Mildred Avenue Middle School in Mattapan.
He had left a previous school after he and another student allegedly tried to pick a fight with another teenager. Police said they had been to his house several times, usually after his mother had called, desperate for help with controlling him.
Last June, police went to their Mattapan home after the 14-year-old allegedly slapped his younger brother in the face and threw him to the ground. His older teenage sister told police that he then pushed his mother to the ground and threatened to kill her.
In court Monday, Peña, a tall, husky boy with his long brown hair in a ponytail, wore glasses and a button-down shirt and tie. His mother, Betty Nuñez, and his older sister sat behind him and exchanged silent glances with him.
“He’s very scared,” Doolin said of his client. Doolin described Peña’s family as very supportive and loving.
At the time of the shooting, Nuñez was outside warming up the car so she could take Juanly to an appointment for a home-schooling program. It was a school day, but Janmarcos had asked to stay home because he wanted to be with his mother, Polumbaum said.
After the shooting, Peña began calling 911, but asked his sister, who had heard the gunshot from her room, to call instead. He then ran out of the house and made it nearly a mile to Walk Hill Street before police caught up with him. Peña was still holding the weapon and the magazine.
He waived his Miranda rights and, with his mother present, gave police a detailed account of what happened, Polumbaum said. He was less forthright about how he obtained the gun, Polumbaum said.
“Juanly was pretty vague about that part,” he said. Polumbaum said police are still trying to find out how Peña got the gun.
Janmarcos’s killing galvanized police and city officials, who revived a gun buyback program and vowed to stem the flow of illegal firearms.
Still, the rate of crime among children between 10 and 17 continues to drop in Massachusetts and the nation, according to statistics compiled by the National Center for Juvenile Justice and the US Department of Justice. In Massachusetts, the rate of property and violent crimes fell by nearly half between 2002 and 2012.
“These are really rare kind of cases,” said Naoka Carey, executive director of Citizens for Juvenile Justice in Boston. “They’re upsetting and shocking, but there just aren’t that many of them.”John R. Ellement of the Globe staff contributed to this report. Maria Cramer can be reached at email@example.com.