BATON ROUGE, La. - Two Baton Rouge police officers acted in self-defence and were justified in fatally shooting a man who shot and wounded them after a car chase in February, a prosecutor said Monday as his office released dramatic video of the gunbattle.

Dashcam video from the officers' cruisers shows the suspect, 22-year-old Calvin Smith, exit his vehicle and immediately open fire on the officers with a semi-automatic rifle as they pulled up to Smith's parked car at the end of the chase.

The officers returned fire, fatally wounding Smith, according to a report released Monday by East Baton Rouge District Attorney Hillar Moore.

The report says at least 54 shots were fired during the Feb. 13 shootout, which lasted less than 20 seconds. The suspect fired at least 20 shots from an AR-15 rifle, while the officers fired at least 34 shots between them from their semi-automatic pistols, Moore's report said.

Moore said he had "no idea" how the officers survived the shooting. Officer Theodore Smith was shot once in the abdomen, and his vehicle was struck by three bullets; Officer Sean Garic was hit in the head by one of the rifle shots, and his vehicle was hit by eight bullets, according to Moore's report.

"All I can say is that God must have been with them and protected them," Moore said at a news conference.

Video from Officer Smith's body camera shows him putting his cruiser in park and exiting his cruiser when the gunfire erupts. After an initial burst of gunfire, the officer began running as another volley of shots erupted.

"Shots fired! Officer hit!" Smith shouted over the blaring of sirens after the gunfire ended.

Smith crouched down next to a vehicle and radioed in a plea for paramedics to come to the scene.

"Two officers hit!" he shouted.

Calvin Smith died at a hospital hours after the shooting. The officers were released from the hospital less than three days after.

The officers were responding to a domestic disturbance when Smith led them on a chase through a neighbourhood that ended outside his home.

The chase began after the mother of Smith's ex-girlfriend called 911 to report that Smith had damaged her car. The mother's boyfriend had fired two shots in Smith's direction before he fled, but nobody was injured in that initial shooting, Moore's report said.

Gina Chambers has said Calvin Smith, the son of her godmother, had been living at her Baton Rouge home since December after recently moving from Shreveport. On the morning of the shooting, Chambers told reporters that Smith has been grappling with "mental issues" and had attempted suicide.

Moore's report on the shooting said Smith had severe depression and recently stopped taking his medication after developing "adverse" side effects in recent months. A recent break-up with his girlfriend caused him "great distress" and exacerbated his mental health problems, according to the report.

Moore said Smith had been on probation for a 2014 conviction in East Baton Rouge Parish for indecent behaviour with a juvenile.

Smith was black; one of the officers is white and the other is black, according to Moore.

Moore said he met separately with Smith's mother and other relatives and with the two officers who were wounded before releasing his findings and posting a link to the video of the shooting on his office's website. Moore said it was "extremely emotional" for Smith's relatives to see the footage.

"They indicate that the person who fired at these officers was in no way the child that they raised and the child that they knew," Moore said. "The family was very concerned for the safety of the officers, and they were sorry that Mr. Smith had placed them in this position."

News from © The Associated Press, 2016