The Boston Police Department says the 19-year-old died as he tried running away from officers conducting an anti-gang sweep in the area of Navillus Terrace and Winter Street around 9:41 p.m. on Saturday.
In a statement, police said: "While conducting [interviews] of the group, a male suspect fled from the group and was pursued by officers. In the course of the pursuit, the suspect turned around and there was an exchange of gunfire. During this exchange, the suspect, a 19 year old male, sustained fatal injuries."
Police recovered a gun; the incident is now under investigation by Boston Police, State Police and the Suffolk County District Attorney's office.
The department did not say how many officer fired at the teen, whose name has yet to be released. No officers were injured.