Mattapan teen admits killing younger brother; turned over to DYS custody until he turns 21

Juanly Pena, now, 15, today admitted he shot his 9-year-old brother to death in February, the Suffolk County District Attorney's office reports.

Pena was sentenced to DYS custody until he turns 21 - with a three-year prison sentence after that suspended if "he obtains a GED and/or employment, undergoes a mental health evaluation and treatment, refrains from any contact with persons he knows to be gang members and does not incur any new criminal charges during that time," the DA's office reports.

According to the DA's office:

Had the case proceeded to trial, [Assistant DA Ian] Polumbaum and fellow ADA Beth Keeley of the DA’s Child Protection Unit would have introduced evidence to prove that on Feb. 7, Janmarcos Peña begged his mother to let him stay home from school with her; Juanly Peña was also home, as he had not attended school most of the winter. Peña 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, Peña 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.

Peña 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.