Jamie Petrolini, 19, claimed within hours of moving in that he had gone to London to kill to qualify for the SAS, Andrew Connor, a fellow A- level student at Petrolini's Oxford crammer, said.
During the confession, made almost a month after Mohammed el-Sayed, a father of two, was found in Bayswater, west London, slumped in his car with his throat slit and 12 stab wounds to his chest and arm, Petrolini showned no remorse. 'He thought he was a demi-god because he had no morals,' said Mr Connor. 'He did not think killing was wrong.' Mr Connnor claimed Petrolini said that he felt an adrenalin rush after the killing and, on the way back to Oxford, he and Richard Elsey, 19, accused with Petrolini of murdering Mr el-Sayed, 44, smiled at each other.
Later Petrolini wrote to Mr Connor from prison insisting that he was a 'kind, chilled, gentle person' but that he had been under the control of Elsey, a 'real-life version of Hannibal Lecter'.
The prosecution claims Elsey restrained Mr el-Sayed while Petrolini slit his throat and stabbed him. The teenagers, students at Modes Study Centre, allegedly jumped into his car when it stopped at a junction on 14 January this year.
Petrolini's principal was informed after he repeated his confession to Mr Connor and another flatmate and showed them blood-stained gloves. He also gave Mr Connor a book on how to kill a man and left a note with a smiley face in his bedroom with the message 'please help me'.
The jury heard that within days of moving in Petrolini lost his obsession with the SAS. Mr Connor said Petrolini began to want to play guitar and dress like he did. Petrolini later sent Mr Connor a Nirvana poster from prison depicting himself as Kurt Cobain, the cult grunge band's lead singer who died in April, and Mr Connor as a member of the band. A letter contained Nirvana lyrics including an invitation to eat his cancer now he was black inside.
Days before he confessed to Mr Connor, Petrolini told Luke Munton at a nightclub that the SAS let him slit the throat of an Egyptian businessman as a birthday present. Later he wrote to Mr Munton from prison claiming Elsey was a 'lying, psychotic, murderous bastard' who had got inside his head.
Elsey, of Beaconsfield, Buckinghamshire and Petrolini, a former Gordonstoun pupil, of Grantown-on-Spey, Highland, deny murder. Petrolini has admitted the killing on the ground of diminished responsibility. Elsey claims he thought Petrolini was only going to rob Mr el-Sayed.
The case continues today.