A FORMER pupil of the Prince of Wales's old school, Gordonstoun,

stabbed a stranger to death as the ''ultimate dare'', a jury heard

yesterday.

Jamie Petrolini and Richard Elsey, both 19, jumped into a car driven

by 44-year-old chef Mohamed el-Sayed when it paused at a Give Way sign,

the Old Bailey was told.

While Mr Elsey held the Egyptian-born chef from behind, Mr Petrolini

slashed his throat with a commando knife and stabbed him repeatedly in

the chest, said Mr David Calvert-Smith, prosecuting.

Mr Petrolini, the former Gordonstoun pupil, of Grantown-on-Spey, and

Mr Elsey, of Beaconsfield, Buckinghamshire, both 19, deny murder.

Mr Calvert-Smith said Mr Petrolini was on a high after the murder in

Bayswater, London, in January this year, and later told a friend there

was ''a lot of blood which spurted out like in films''.

After the killing, on the night before Petrolini's 19th birthday, the

two men caught a bus back to Oxford where both were retaking science

A-levels at a private tuition college, the jury heard.

''When they boarded the bus that night they had to all intents and

purposes committed the perfect crime. Who was going to suspect two young

men doing A-levels in Oxford?'' asked Mr Calvert-Smith.

But, the court was told, whether ''through conscience or boasting'' Mr

Petrolini could not keep what happened to himself and told several

friends.

The two men had become close friends after meeting at the college. Mr

Calvert-Smith said: ''The one thing in common which came to dominate

their thoughts and spare time was the Army.

''Their interest in the Army, the paratroopers and the SAS developed,

the Crown suggest, into an unhealthy obsession, and seems to have

resulted in their facing this terrible charge of murder.''

During their first term at Oxford, the two carried out a series of

pranks to ''prove their manhood, initiative or courage'' When they

returned after the Christmas holidays ''plans were laid by the two for

their next dare -- what might be called the ultimate dare. They decided

to travel to London where Petrolini would kill a man to prove his

mettle.''

Mr Calvert-Smith said the murder weapon was a commando dagger Mr

Petrolini had bought Mr Elsey as a #30 Christmas present.

Their alleged victim, Mr el-Sayed, had spent the evening at a

Bayswater casino with a friend and was on his way home to his wife and

two children when the two men struck.

Mr Calvert-Smith said that Mr Petrolini leapt into the passenger seat,

holding a knife to Mr el-Sayed, and let Mr Elsey into the back. Further

down the road he ordered the driver to stop, and slashed his throat,

while Mr Elsey held him from behind, and stabbed him in the chest.

The court was told that the body was not found until the morning by

which time his killers were back in Oxford.

Mr Petrolini and Mr Elsey later played a sick prank in a hamburger

restaurant with a girl they knew, Mr Calvert-Smith said.

Mr Petrolini told Mr Elsey to shut his eyes and got out Mr el-Sayed's

spectacles, which he had taken from the murder scene, and put them on.

He put fake blood in his mouth and told Mr Elsey to open his eyes, then

he spat the blood on the table and laughed.

Mr Petrolini told the girl: ''It's a private joke.''

When Mr Petrolini moved lodgings he told his new companions about the

murder, saying Mr Elsey had told him to kill the man, described the

stabbing, and produced bloodstained gloves and keys.

The next day the college was informed and police interviewed Mr

Petrolini.

Mr Calvert-Smith told the jury that in a book Mr Petrolini recorded

details of how to stab someone. One entry involved cutting the throat

below the Adam's apple which was what happened to Mr el-Sayed.

The court heard that in Mr Elsey's room police found the commando

knife stained with Mr el-Sayed's blood.

Mr Peter Thornton QC, defending Mr Petrolini, said his client was

pleading not guilty to murder because of his mental state at the time,

but guilty of manslaughter on grounds of diminished responsibility.

He added that Mr Petrolini had gone to Gordonstoun with great promise

but had failed to fulfil it and had set his heart on a military career.

Mr Elsey was going to help him achieve that and he regarded him as a

hero, believing he was in the paras.

Mr Elsey encouraged him in daring deeds, climbing a crane at night,

stealing a radio, and impersonating a police officer.

Because of his mental state, Mr Petrolini was ''persuaded to do the

impossible, to kill someone and escape detection as part of the ultimate

initiative test. Elsey told Petrolini what to do and he did it,'' said

Mr Thornton.

The trial continues.