FALL RIVER — Bristol County DA Thomas M. Quinn III said his office has determined that a cab driver acted in self-defense when he shot and killed one of two men trying to rob him during a botched Aug. 10 holdup in New Bedford.

"After a thorough investigation, it is clear that the cab driver acted in lawful self-defense and the use of deadly force was justified under the circumstances," Quinn said in a statement released to the media Wednesday at the Superior Court arraignment of 23-year-old New Bedford resident Kyle S. Dawson, the surviving robbery suspect.

The cab driver for the Yellow Cab Co. picked up Dawson and Christopher Dunton, 24, of New Bedford about 1 a.m. in the area of Cottage and Willis streets and drove them to Bentley Street in New Bedford's near North End, four houses away from Dawson's home, prosecutors said.

Dawson asked the cab driver if he had change for a $50 bill and then Dunton placed him in a chokehold, while Dawson held a knife to his side, prosecutors said. The cab driver freed himself and fired three rounds into the cab, killing Dunton, investigators said. Dawson ran out the passenger side and door and was arrested later that day by police.

"The victim was violently robbed by two men who threatened his life while choking him and putting a knife to his side," Quinn said in the statement. "Fortunately, he was able to extricate himself and get out of the cab.

"He still faced a potentially life threatening situation and fired three shots from a handgun he was lawfully entitled to possess and carry," the DA said.

Quinn said the cab driver was robbed previously and his close friend, Donald DePina, also a New Bedford cab driver, had been "brutally murdered" while driving his own cab in 2015. "The loss of any life is tragic, but I hope the cab driver and Mr. Dunton's family can move forward with their lives," Quinn said.

In early October, a Bristol County Grand Jury indicted Dawson on a charge of involuntary manslaughter and other charges in connection with Dunton's death. He is also charged with armed assault with intent to rob and two counts of assault and battery with a dangerous weapon.

On Wednesday in Superior Court, prosecutors asked that Dawson be held without bail for a dangerousness hearing on Nov. 8. Judge Mark A. Hallal granted prosecutors' request. If found to be dangerous, Dawson could be held without bail for up to six months as he awaits trial.

Not guilty pleas were entered to all the charges on Dawson's behalf. Involuntary manslaughter carries a maximum sentence of 20 years in prison, if convicted.

Follow Curt Brown on Twitter @CurtBrown_SCT