Braintree Police report the teen was shot around 4:40 p.m.; she is expected to survive.
Police say two suspects were taken into custody. NBC Boston reports the two men were shooting at each other as part of an argument that spiraled into gunfire between two groups of about six to seven men each.
Police locked the mall down - people in stores were told to stay there. Residents of surrounding neighborhoods were told to shelter in place.
Police believe this was a targeted shooting and not an active shooter situation at the mall today.
Both orders have since been lifted.