The bullet had fractured the left thigh bone of Sergeant Alan Jones, 36, and lodged in the bone. There was severe blood vessel injury to the groin. On several occasions during his slow recovery, his condition became critical due to the effects of extensive muscle damage. There were periods of impaired function of the kidneys and lungs and at a time when he was on renal dialysis.
Sgt Jones told the Old Bailey that he and Sgt Ian Roberts were driving a police car in Paddington, west London, on 19 December last year, when they decided to follow a blue Ford Sierra.
As they reached a slip road leading to the A40, they ordered the car to pull over and began questioning the driver, Robert Fallon, 35, and his passenger Christopher Danaher, 34.
Sgt Jones said he decided to search Mr Fallon after Sgt Roberts said the car's tax disc appeared to have been altered.
Sgt Jones said: 'I started searching him from the legs upwards. Mr Fallon spun around all of a sudden, which took me by surprise and immediately I took a step backwards. I saw he had the gun held at waist level. He pulled the trigger, the gun went off and I was hit in the groin.'
Orlando Pownall, for the prosecution, said Mr Fallon and Mr Danaher fled on foot, Mr Fallon throwing away his green Barbour jacket which contained an axe and a Stanley knife. He said a loaded, sawn-off pump action 12-bore shotgun was found in the car.
The next day both men surrendered to separate police stations. Mr Fallon told police: 'The firearm just went off when the police officer tried to grab it. I didn't intend to hurt anyone.'
Mr Fallon, of Eton Avenue, Wembley, north-west London, denies attempted murder and an alternative charge of causing grievous bodily harm with intent to resist arrest. Mr Danaher, of Wembley Way, also Wembley, denies conspiracy to rob. They both deny theft of the car and two charges of possessing a firearm with intent to endanger life.
The trial continues today.