Father Darren Croxton was stabbed three times from behind following an organised fight in Hailsham, a court was told.
The 26-year-old suffered two “superficial” wounds to the rear of his right thigh, with the fatal wound severing an ephemeral artery in his left thigh, a jury at Lewes Crown Court heard.
Pathologist Dr Olaf Biedrzycki gave evidence into the wounds Mr Croxton suffered on January 22, 2012.
Dr Biedrzycki told the court he believed Mr Croxton was wounded with a bladed weapon with a single cutting edge which was at least eight inches long.
A commando knife fitting that description, which was discovered in defendant Stuart Johnson’s bedroom two months after the incident, was paraded before the court.
Johnson, 19, of no fixed abode, denied the prosecution’s claim it was the murder weapon. He and a teenager, who cannot be named for legal reasons, deny the charge of murder.
A second knife exhibited as evidence was found in an alleyway in Hailsham on January 26, 2012.
Dr Biedrzycki was unable to give evidence on the knife which caused the fatal wound because of medical intervention to Mr Croxton.
He told the court: “The cause of death was due to different organ failure and injuries to the brain where it suffered damage through lack of oxygen, the cause of which was the heart stopped beating and the cause of that was haemorrhaging blood from the left thigh.”
Simon Russell-Flint, defending the youth in the case, suggested Mr Croxton had inflicted the wounds to himself.
He asked Dr Biedrzyck: “If the deceased had a knife in his right hand and a person was standing behind him, isn’t it quite feasible for the deceased to have inflicted those wounds on himself [as he struck out at the assailant].”
Dr Biedrzycki answered no. He said: “Yes people can stab themselves but you are suggesting he stabbed himself three times. I do not think he inflicted the wounds.”
Defence barrister Alan Kent said: “What’s important is there were three stab wounds. Two were superficial and described as through injuries to the thigh. The other was not superficial because it penetrated between five-eight centimetres and cut an ephemeral artery.
“It’s always been the crown’s case the injury to the artery was caused in the clearing at the time of the fight and blood evidence supports such a contention; in other words it was before Darren Croxton started running.”
The trial continues.