Juanly Pena, 15, pleaded guilty on Aug. 20 to killing his younger brother. Photo: Globe/Pool
A Mattapan teen admitted on Wednesday to killing his younger brother at their home in February.
Juanly Pena, 15, was charged as a youthful offender for the Feb. 7 shooting death of his 9-year-old brother, Janmarcos Pena, and after pleading guilty to manslaughter and unlawful possession of a firearm was ordered into the custody of state Department of Youth Services until he is 21.
Prosecutors say the teen was recklessly handling the gun when it went off, and thought the gun was unloaded when he pointed it at his brother’s heart.
An investigation revealed that no one else in the home knew he had the gun, according to the Suffolk district attorney’s office.
Had the case proceeded to trial, prosecutors would have introduced evidence to prove that on Feb. 7, Janmarcos Pena begged his mother to let him stay home from school with her; Juanly Pena was also home, as he had not attended school most of the winter.
Pena walked into the home’s den carrying a semi-automatic handgun; he had removed the magazine but was unaware that a live round remained in the chamber.
Standing within two to three feet of where his younger brother sat in a chair playing video games, Pena squeezed the trigger, firing a shot that struck Janmarcos in the upper chest, traveled down his torso, and exited his lower back. Janmarcos ran into the hall and collapsed.
Pena began to dial 911, but handed the phone to his sister and fled the home. Before he left, he reloaded the gun with the magazine containing one live round of ammunition, Polumbaum said. Boston Police caught up with Peña on Walkhill Road a short time later.
He informed officers that he was carrying a firearm.
Janmarcos was rushed from the scene by ambulance but pronounced dead at a hospital.
Illegal gun purchase
During a post-Miranda interview with his mother present, Pena told police that he had met someone at an MBTA station a day prior and was at that time introduced to another person who provided him with the firearm. That gun was matched to the bullet that killed Janmarcos and to a shell casing found in the room where the shooting occurred.
Pena was also sentenced to a three-year state prison sentence suspended until the age of 24.
If he obtains a GED or employment, undergoes a mental health evaluation and treatment, refrains from any contact with alleged gang members, and does not incur any new criminal charges during that time, he will not serve the prison sentence.
If he violates those terms, however, he could be ordered to serve out the three-year sentence as an adult in state prison.
The shooting of the young boy sparked the push for a citywide gun buyback program that was launched earlier this year and has so far collected hundreds of guns.