A police department in California has released footage of the moment cops shot and killed an unarmed teenager, with several shots fired while the victim was lying on the floor. Body camera footage from the Fresno police department captures the shooting of Dylan Noble, 19, who was killed after a traffic stop when police believed he was armed.

The footage shows police shouting at Noble and telling him he will be shot unless he shows both his hands and gets down on the ground, then shooting him twice, and twice again after he is down – which police claimed was due to him reaching towards his belt.

The victim's mother has filed a complaint against the police department, and has accused them of using excessive force, CBS Los Angeles reported.

Fresno chief of police Jerry Dyer told the TV station the teenager had one hand behind his back at the time of the shooting and police were concerned he could be concealing a weapon. However, Noble was not carrying a weapon but had been holding a small plastic box in his right hand.

The incident took place on 25 June, but footage has only just been released following a public backlash against the shooting, and the incident is being investigated.

However, police in the high-profile shootings of black men Philando Castile and Alton Sterling, both fatally shot by police earlier this month, have not released body camera footage despite public outrage over the incidents.

Chief Dyer told ABC30: "I anticipate the district attorney's investigation to be done by August. I've asked everyone to expedite. Internal affairs will then make its conclusion and then I'll make a decision. This is a promise to the community. I promise you I'll make the right decision," said Dyer.

The officers were allegedly in the area after hearing reports of a man carrying a rifle in the street, but had pulled the teenager over for a traffic stop Chief Dyer referred to as 'high risk'. Noble allegedly continued driving for half a mile after he was told to pull over.

Series of filmed shootings by US Police

The footage is the latest in a series of police shootings that have been filmed – with footage in other cases shot by passers-by, and one film live-streamed to Facebook by the victim's girlfriend.

The footage of the shooting has caused a backlash against the methods used by US police, in particular by the group Black Lives Matter, which has highlighted the disproportionate amount of black people killed by police.

Because of the controversial nature of the shooting, Noble's family agreed to delayed the release of the footage by one week after the fatal shooting of five Dallas police offices which allegedly came as a response to the police shooting of a string of unarmed black men over the course of several days.