A 17-year-old Dorchester teen is facing multiple firearm charges after Boston police say officers spotted him walking stiffly with both arms pinned to his sides near Theodore Street in Mattapan, then chased him down Marden Avenue as he tossed a loaded Polymer80 pistol into a nearby backyard. Investigators searched behind the residence and recovered the gun, which they say was loaded with 15 rounds, including one already in the chamber.
According to Boston 25 News, officers patrolling the area of Middleton Street and Norfolk Street on August 22 noticed two juveniles walking toward them near Theodore Street. Police said they were already familiar with both teens from previous interactions. One of the pair began acting differently and walking awkwardly, according to police, prompting additional officers to stop him on Theodore Street.
Police said the teen then removed an object from his waistband and ran down Marden Avenue before throwing it into the backyard of a nearby residence. District detectives responded to process the firearm, which Boston police identified as a Polymer80 semi-automatic 9mm pistol. The Boston Police Department’s own account of the incident, released the following day, adds that officers observed the suspect’s arms pinned to his sides during the initial approach, a detail that first raised their suspicion, as described in the Boston Police Department’s release.
Charges Stack Up for the Teen
The 17-year-old now faces charges of carrying a firearm without a license, carrying a loaded firearm without a license, possession of a large-capacity firearm, and possession of ammunition without an FID card. Boston police did not release his identity because of his age. He is expected to be arraigned in Boston Juvenile Court, though the felony nature of the charges means prosecutors could evaluate a Youthful Offender indictment under Massachusetts General Laws Chapter 119, Section 54, a provision that lets juveniles aged 14 to 17 accused of felony gun crimes be tried under adult sentencing guidelines rather than standard delinquency procedures, as Hoodline has previously reported on a similar Dorchester case.
The stakes are significant. Under Chapter 269, Section 10(a) of state law, carrying an unlicensed firearm outside one's home or business carries a mandatory minimum of 18 months in jail for adult offenders, with sentences reaching up to 5 years in state prison, according to Geraghty Law, LLC. Separately, the large-capacity magazine charge falls under Chapter 269, Section 10(m), which criminal defense attorneys note carries a state prison sentence of 2.5 to 10 years and a mandatory minimum of one year, since Massachusetts law bans feeding devices holding more than 10 rounds.
Part of a Ghost Gun Crackdown
The Polymer80 brand at the center of this arrest has become a recurring name in Boston gun cases because it allows people to assemble untraceable firearms at home without a factory serial number. Massachusetts lawmakers targeted exactly this problem when Governor Maura Healey signed An Act Modernizing Firearm Laws in July 2024, a measure that now requires all privately manufactured firearms to be serialized and registered, per reporting from WWLP. A Boston City Council update this past June found that law enforcement agencies across the city had already recovered 54 such ghost guns, underscoring how common the unserialized weapons have become on Boston streets.
Statewide, the Boston Police Department has led every law enforcement agency in Massachusetts in crime gun submissions, turning in 550 seized firearms to state authorities in 2024, with 9mm handguns the most commonly recovered caliber, according to the Commonwealth Fusion Center's 2024 Crime Gun Report cited by the Massachusetts Legislature. District B-3, headquartered at 1165 Blue Hill Avenue, covers Mattapan and North Dorchester and has kept up targeted patrols aimed at youth gun violence in the area.
Latest in a String of Teen Gun Arrests
This is not an isolated incident for the district. Just five days earlier, on August 17, District B-3 officers arrested another 17-year-old carrying a loaded gun during a patrol stop on Michigan Avenue in Dorchester. And in May, officers in neighboring District C-11 arrested a 16-year-old in Dorchester after a ShotSpotter activation led them to a loaded Polymer80 9mm ghost gun, a case Hoodline covered in its report on the Dorchester teen’s ghost gun arrest.
It remains unclear whether the Mattapan teen was previously under electronic monitoring or probation, a circumstance that has surfaced in other recent Boston juvenile gun cases, or whether detectives will pursue additional charges tied to tracing the origin of the Polymer80 kit. Boston 25 News described the case as a developing story, and the outlet's reporting credits Keenan Bassma with the original account.
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