BRAINTREE — Robert L. Dussourd had been fighting at home with his girlfriend off and on for hours when he was told early Thursday morning to leave their home on Liberty Street.

His girlfriend urged him first, and then her father, Robert Kelley, said he instructed the 44-year-old Dussourd to go.

“She told him he had to leave and then I told him he had to leave and I got him to walk out,’’ Kelley said Thursday afternoon.

As Dussourd walked into the darkness at about 1:20 a.m., he declared he had a knife and planned to slash his girlfriend’s tires, Kelley said. His daughter then called Braintree police.

Officers arrived with a police dog and found Dussourd hiding under a parked car in the driveway of a neighboring residence on East Division Street, the Norfolk district attorney’s office said.

Police tried to talk Dussourd into surrendering, but he emerged from underneath the car brandishing a knife, which he continued to hold even after officers fired at him with non-lethal bean bags, according to David Traub, a spokesman for District Attorney Michael W. Morrissey.

A man who lives nearby said he heard officers yelling, “Show me your hands.’’

“I heard someone reply, ‘I have a knife! Just shoot me!’ ’’ said the neighbor, who asked not to be identified. “Several shots rang out.’’

Police shot Dussourd at 2:08 a.m.

Officers tried to save him, but he later died from his injuries at South Shore Hospital in Weymouth, Traub said.

“The information we have at this time indicates that he came out from under the motor vehicle brandishing the knife,’’ he said. “At that time, the officers began what unfortunately proved to be an unsuccessful attempt to deescalate the situation using nonlethal force.’’

Two Braintree officers were involved in the final confrontation, Traub said, but how many fired their weapons and how many shots were fired are part of an investigation.

In a statement, Morrissey promised a thorough inquiry into the officers’ use of deadly force.

“While we are a long way from being done with this investigation, it is important in the case of a police shooting to provide information to the public, even if that information is preliminary in nature,’’ he said. “Every police shooting demands a full, deliberate, and fair investigation and that is what we are doing here.’’

Kelley said Dussourd had struggled with alcohol and unemployment. He said he does not know what happened between Dussourd and the officers.

“I wasn’t there,’’ Kelley said.

The district attorney’s office declined to comment on the domestic disturbance that preceded Dussourd’s death.

Court records show Quincy police arrested Dussourd on June 3, 2012, on assault and battery and witness intimidation charges after a woman said he grabbed her shoulders, put his face against hers, and threatened her inside their apartment. The case was later dismissed.

A day later, the same woman received a restraining order against Dussourd, according to records filed in Quincy District Court.

The Globe is not identifying the woman because the district attorney’s office declined to say whether she was the same woman involved in the domestic disturbance with Dussourd immediately before Thursday’s shooting.

In an affidavit filed with the restraining order, the woman wrote that Dussourd’s “drinking has become uncontrollable’’ and she feared for him, herself, and their children.

The record shows that the mandates Dussourd had to follow were changed several times while the order was in effect.

In July 2012, the woman requested Dussourd be permitted to contact her, but she returned to court in October and got a modification that made it illegal for him to contact her.

The order is no longer in effect, records show.

A woman who answered the door at the home of one of Dussourd’s relatives in Quincy declined to comment Thursday.

Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her on Twitter @lauracrimaldi. John R. Ellement can be reached at ellement@globe.com. Follow him on Twitter @JREbosglobe.