Mississippi authorities have released body camera footage showing how a toddler was fatally shot by a police officer responding to a report of shoplifting in a Walmart car park.

Kohen Wiley, aged one, was on his mother’s lap in a moving car when officers surrounded the vehicle in the city of Senatobia on 14 June.

The state’s attorney general found the policeman was justified in using force, and the officer’s lawyer argued in a statement to the BBC that the driver was attempting to kill law enforcement.

The child’s family disputes that the shooting was justified. Their lawyer, Ben Crump, has called the police response “excessive from the very start”.

Crump said an allegation of shoplifting “does not warrant the death” of a child.

Kohen Wiley was riding in the vehicle with his mother, Vellesiya Wiley, and another woman at the time of the incident.

Senatobia Mayor Greg Graves confirmed to the BBC’s US partner CBS that Hunter Foster, the officer who opened fire, had resigned.

The Senatobia Police Department did not immediately respond to the BBC’s requests for confirmation.

The footage released by Mississippi authorities on Thursday shows a first-person perspective of the officer who opened fire.

After being told by a staff member that suspected shoplifters were getting away, five law enforcement officers run towards the car with guns drawn.

The vehicle reverses, crashing into a parked car, before pulling forwards.

The officer wearing the body camera raises his gun and aims it at the moving vehicle as he runs closer, shouting: “Stop!”

As the car closely passes the officer, he fires his gun, shattering the passenger-side window.

Four gunshots can be heard, as police command the driver to stop. The car continues to drive off slowly through the car park.

CCTV video from the storefront appears to show that at the moment the policeman opens fire, another officer is standing near the front of the moving vehicle.

“The driver of the vehicle was attempting to kill those 5 officers,” Martin Zummach, an attorney representing the officer, said in a statement to the BBC, adding that his client “had no choice but to discharge his weapon”.

“We are very sad for the loss of life,” Zummach said. “But the outcome of the investigation was not only expected, but it was overdue.”

The child’s mother, Wiley, has denied she and her friend stole nappies from the store. No charges have been filed against them.

The boy’s death has sparked protests and vigils in Mississippi.

At a news conference, relatives demanded accountability.

“After what I’ve seen today, I’m having a difficult time understanding the word, ‘justified,’ said LaSandra Williams, Kohen Wiley’s grandmother.