Astonishing footage has emerged of the moment a Good Samaritan shot and killed a man who was attacking a police officer in the middle of the road.

Ashad Russell has been called a hero after he gunned down armed suspect Edward Strother while he was beating Deputy Dean Barde on the ground in Estero, Florida.

The newly-released video of the November shooting shows Strother pinning Deputy Bardes to the road after the cop chased him several miles on I-75 before finally pulling him over.

Motorists stopped to watch the incident unfold, and some took their phones out and started filming.

But Russell decided to take the matter into his own hands, and took out his gun instead.

Officer Barde can be heard pleading: 'Shoot him! Shoot him!' as he struggles with Strother on the floor.

Astonishing footage has emerged of the moment a Good Samaritan shot and killed a man who was attacking a police officer in the middle of the road. This image shows suspect Edward Strother pinning Deputy Dean Barde down after a high speed chase in Estero, Florida

Ashad Russell (left) then stops his car at the scene, gets out and approaches the pair as they tussle on the ground (right). He then draws his gun and aims at Strother. In the video, Barde can be heard pleading for Russell to shoot Strother

Footage shows Russell (left) edging towards the suspect before firing three shots, all of which hit Strother. The moment he drew his gun on the suspect was caught from different angles from two witnesses

Russell, who has a concealed weapons permit, steps out of his car raises his gun, and fires three shots, all of which hit Strother.

Seconds later, Russell dropped his weapon and slowly walked away to wait for first responders to arrive.

On the film three shots clearly ring out as the witnesses describe seeing Strother on top of the cop.

Medics rushed Strother to the hospital where he was later pronounced dead.

A total of around a dozen photos and videos were handed over to the state attorney’s office.

They determined the shooting was justified with the life of the deputy in danger.

Lee County Sheriff's Office released a single photograph of the incident, praising Russell as a 'hero'.

Strother (left) is seen up right over Barde as Russell approaches. The suspect is seen (right) lying on the ground after getting hit, and Barde stands up

Medics rushed Strother to the hospital where he was later pronounced dead

Strother, 53 (left) died in hospital from his injuries. Deputy Sheriff Bardes (right) was not seriously hurt because of Russell's actions. His colleagues have thanked Russell for stepping in

Lee County Sheriff Mike Scott hailed both the deputy and his savior as heroes in an emotional Facebook post about the attack.

He revealed how Bardes, who usually brings recruits along with him to train, was working alone.

'Earlier this week, two heroes met on I-75 and while they had never met before, one would save the others life.

'Ironically, this was the first day in a while that Deputy Bardes was alone on patrol because as a Field Training Officer, he typically has a recruit riding with him to learn the business,' he said.

Thanking the man who saved his colleague's life, Sheriff Scott said: 'I thank the hero that recognized the imminent threat, rushed to Deputy Bardes’ aid, and ultimately stopped that threat.

'In a day and age where race is a near instant focus for media and other pundits in police incidents, the fact is that this hero happens to be a man of color who stopped another man of color from further harming or killing a white cop; thereby reminding us that black lives matter, blue lives matter, and indeed all life matters.'

The man's gun was seized as evidence but replaced immediately by Shoot Straight, he added.

Bardes was taken to hospital alongside his attacker but did not suffer serious injuries.

Not a single 911 call was made from the scene.

Dozens of police descended on the scene after Strother was shot and killed last year