Kenneth Noye kicked Stephen Cameron in a "rain of blows" as he lay dying from a stab wound, the Old Bailey was told yesterday.
Jonathan Saunders, who was driving a milk tanker on the day of the killing in May 1996, told the jury that Mr Cameron, aged 21, was left slumped in a pool of blood on the road as Mr Noye drove away from the scene in his Land Rover Discovery.
He said he sounded his horn repeatedly at Mr Noye and Mr Cameron as they scuffled on a slip road off the M25, near Swanley in Kent. "One of them seemed to be on the ground at this point while the other one still seemed to be raining blows, kicking and thumping," said Mr Saunders.
"This went on for about 10 to 15 seconds. The older gentleman [Mr Noye] then walked back to his vehicle, got in and drove away in the normal driving manner. I saw his face as he drove past me, and I didn't see any injuries to his face."
Another witness told the court that Mr Cameron's finacÃ©e, Danielle Cable, tried to pull him away from fighting moments before he slumped with his stab wound. "I remember her jumping out from the driver's side of a red van and dashing towards the taller of the men, fighting and pulling him away," said Catherine Elliot.
"She was screaming. I think she got him by the arm. She succeeded. The two men separated. He was stumbling, obviously in a very distressed state. He stumbled down by the front passenger side of our BMW," said Mrs Elliot.
"He was holding his stomach, his arms outstretched. He was in dark clothing - there was a mass of wet which I assumed was blood. He got up and stumbled round the side of our vehicle and fell down in front of the red van."
Mrs Elliot said Ms Cable was screaming and pleading to people: "Someone help, someone help me, he has been stabbed." Mrs Elliot said she first saw two men fighting as her car approached the interchange. "They were fighting very close up to each other - arms up, heads bobbing up and down. They were in close contact, getting more agitated. It was quite fierce stuff really."
She said the second man disappeared after Ms Cable pulled her fiancÃ© away.
Mr Noye, 52, from Sevenoaks, Kent, denies murdering Mr Cameron, from Swanley, Kent, on 19 May 1996. He claims he acted in self-defence.Reuse content