A 17-year-old boy accused of kicking Liam Hunt in the face during the knife attack that killed him had the murdered Northampton teenager's blood on his shoe.
The teenaged defendant - who cannot be named due to his young age - had blood stains on his right Nike trainer and on the sleeve of his North Face jacket, Northampton Crown Court heard yesterday.
Forensic scientists matched the blood with the DNA profile of Liam Hunt, who died of a seven-centimetre stab wound to the neck in February last year.
The court heard how DNA tests were also carried out on bloodstained clothes seized from three other defendants - but none of them had a positive match for Liam's DNA.
Instead, they all tested positive for blood from one of the defendant's, Kane Allaban-Hamilton, 18, from Camp Hill, whose hand was cut during the attack.
Prosecutor Mr John Lloyd-Jones QC has suggested a 17-year-old defendant kicked Liam in the face after he was stabbed.
Forensic scientist Dr Amanda Sherban was asked how Liam's blood might have got on the teenager's shoe.
She said: "If he was close to Liam when he was bleeding this is what I would have expected... maybe if he kicked out into someone who was bleeding."
The teenager's defence barrister Mr Jo Sidhu QC said: "[My client] was standing in the midst of the brawl when he saw Liam unexpectedly and suddenly appear to lunge towards him.
"[My client] panicked and thought he was about to be attacked. He instinctively kicked out.
"Only after kicking out was he aware that Liam was bleeding from a neck wound. He was unaware that anyone had a weapon or went to the fight carrying a knife."
Dr Sherban said she saw no evidence to suggest this was not a possible scenario.
CCTV has shown how the same defendant arrived at the fight equipped with an electric plug on a white power cord.
A post-mortem also revealed one of Liam's front teeth was chipped in the attack.
The trial continues.