A man accused of murdering a teenager along with three others had been involved in a disagreement with him in the weeks before he was stabbed to death, a court has heard.
Tristan Kerr, 17, from Abertridwr, in Caerphilly, bled to death in the street minutes after being stabbed in the heart and lung with a so-called Zombie knife on 5 February.
Connor Palfrey, 25 from Abertridwr, Georgie Mears, 19, from Thornhill, Cardiff, Elexi Manny, 25 from Senghenydd, Caerphilly, and Ricardo Elliot, 27 of no fixed address, all deny murder through joint enterprise.
Joint enterprise means people who assist or encourage another person to commit a murder can be convicted for the same crime.
Kerr was attacked in the living room of the flat in Lower Francis Street in Abertridwr which was home to Ieuan Crane, 31, the court heard.
Giving evidence from a video-linked room at Newport Crown Court, Crane said Palfrey had what he described as “beef” with Kerr following an incident in which the teenager was said to have chased Palfrey with his dog.
“He [Kerr] was just chasing him,” Crane said.
“At that time there was a beef. A week or two after he went to see Connor Palfrey and they squashed their beef,” he said, meaning they resolved the issue.
On the day the teenager died, Crane said he, Kerr and two other men were sitting in the living room of his flat “just chilling” and playing computer games and watching YouTube when Palfrey and Mears burst in through the unlocked front door.
In a police video interview played to the jury Crane said Palfrey had been armed with a block of wood that “might” have had a nail in it.
He said Mears ran ahead of Palfrey and began attacking Kerr, who had been sitting on a two-seater sofa close to the stairs.
He told officers that at first, he did not realise Mears was armed with what he later described as a “big” knife with a “Zombie, Rambo blade”.
“I thought he was punching him.
“I didn’t see the knife until after the fourth time,” he said.
Crane said he tried to grab Mears’ arm and wrist, but Palfrey threatened him with the block of wood. He said he was trying to stop the attack on his friend.