NEW BEDFORD — Prosecutors say the issue of self-defense is being looked into as part of the investigation into a fatal shooting in New Bedford's North End on Friday.

Before 1:12 a.m. on Friday, a cab driver for Yellow Cab of New Bedford was dispatched to Cottage Street to pick up two male fares, according to Bristol County District Attorney Thomas Quinn. "There was an attempted robbery of the cab driver, allegedly by physical force and with a knife," said Quinn.

The cab driver was stopped in the area of 20 Bentley Street when he was able to escape a chokehold one of the men in the back seat had put him in.

At that point, said Quinn, the driver took out a firearm and fired several shots into the back seat, striking Christopher Dunton, 24, four times. Dunton was found lying on the ground outside of the taxi. He was transported to St. Luke's Hospital where he was pronounced dead on arrival.

The second suspect fled the scene as the driver began firing. "He's alleged to have participated in a violent armed robbery of this cab driver," said Quinn. "I would consider him to be armed and dangerous and would be cautious in approaching an individual who is alleged to have been involved in that kind of violent activity."

Quinn did not provide any further information of the second suspect, who is still being sought by police.

District Attorney Quinn said the cab driver, who has not been identified, is a legal gun owner. The man has not been charged in connection to the incident and is not being held by police. It was unclear if the driver had sustained any injuries during the altercation.

The fatal shooting and attempted armed robbery are under investigation by New Bedford Police and Massachusetts State Police assigned to the Bristol County District Attorney's Office.