A policeman driving a patrol car that killed a woman when it crossed a red light and ploughed into her car could not remember the moments before the crash, a court heard.

PC Nicholas Andrews-Faulkner, 45, of Hassocks, crossed a junction with his siren and blue lights on in his Mitsubishi Shogun 4x4 when he collided with the car being driven by mother of two Karen Stagg.

IT systems manager Mrs Stagg, 47, from East Grinstead, was killed almost instantly and her son Philip, who was a front seat passenger, suffered a broken arm and concussion in the accident in Gatwick Road, Crawley. Mrs Stagg's husband Graeme, 61, was test-driving a BMW just in front of her at the time.

Andrews-Faulkner told Winchester Crown Court he was concentrating on driving despite the distraction of trying to get drunken prisoner George Hildon back to Crawley police station.

Mr Hildon was in the back of the Shogun with PC Malcolm Hyder but had started to bang his head and Andrews-Faulkner, a police officer for 22 years, said he made the decision to put on the emergency sirens to get to the custody area faster.

Christopher Donnellan, prosecuting, said PC Hyder was calm, had the situation under control and had not asked Andrews-Faulkner to take emergency action.

Andrews-Faulkner told the court he feared Mr Hildon would harm himself.

He could remember putting on the siren and lights as he drove away from a set of traffic lights and towards the junction where the accident happened.

Mr Donnellan asked: "Why did you go through the red light at the junction without giving way or stopping?"

Andrews-Faulkner replied: "I cannot answer that question. I have no recollection between putting on the blue lights and the crash. The next thing I knew was the violent noise and the violent manoeuvring of the Shogun."

Mr Donnellan told the court Andrews-Faulkner had given police officers a detailed description of the day in January last year when the accident happened, up until the moments before the collision.

The court has heard Andrews- Faulkner acted "contrary to common sense" by failing to even check at the junction for cars approaching from the adjoining road, Beehive Ring Road, which had a green light to proceed.

Andrews-Faulkner denies causing death by dangerous driving on January 22 last year.

The trial continues.