The MBTA Blue Line Aquarium stop. (James Rojas/WBZ NewsRadio)
Boston Police said a 16-year-old Roxbury boy is now in custody. He is facing four charges of assault with a dangerous weapon, as well as charges of carrying a loaded firearm without a license, possession of ammunition, and discharging a weapon within 500 feet of a building.
His name is not being released because of his age.
The shooting followed some sort of dispute involving a group of teens on board a Blue Line train around 10 p.m. Sunday.
That fight then spilled onto the platform at the Aquarium stop. Two shots were fired, but nobody was injured.
The station was closed overnight as investigators processed the scene, but was reopened Monday morning.