An armed robber pointed a gun at his victim and shouted "Do you want me to blow your chest off?" moments before mistakenly shooting dead his own friend, a court heard.

Daniel Tesfay, 27, is alleged to have shot 20-year-old accomplice Jonathan Barnes in the head after a planned heist of designer watches in Croydon ended in violence.

A jury at the Old Bailey heard that the pair had agreed to pay Jordaan Williams £6,500 for two fake Rolexes, believing they were genuine.

They met Mr Williams at his Morland Road home on August 23 last year but, instead of paying for the watches, Mr Barnes is alleged to have said "Let’s do it" and snatched them from a dining room table.

The court heard that Mr Tesfay then produced a handgun, described by Mr Williams as "like something out of the computer game Resident Evil", from behind a bag.

Mr Williams told the court: "Mr Tesfay took out a handgun and aimed it at my chest. He said ‘Do you know who I am? I’m Murder Mike. Do you want me to blow your chest off? I will shoot you.’"

Mr Tesfay allegedly then pointed the gun at Mr Williams’s friend, Emmanuel Akokhia, before fleeing the room.

Mr Barnes began to follow him but was prevented from leaving by Mr Williams, who grappled with him in a doorway for possession of the Rolexes, the court was told.

The Old Bailey heard that Mr Tesfay aimed his gun towards Mr Williams and fired two shots, one of which hit a staircase with the other striking Mr Barnes in the side of the head.

Mr Williams told the court: "As we were tussling Mr Tesfay lets off two or three shots. I heard a ‘pop pop’ sound. I didn’t think it was a gun shot at first.

"Mr Barnes went limp in my grasp and fell into the dining room."

Mr Tesfay is then alleged to have fled the scene, while Mr Williams called 999 for an ambulance.

The jury were played a 23-minute audio recording of Mr Williams’s phonecall to the emergency services in which Mr Williams and Mr Akokhia are both heard to plead with an operator to "make them hurry up".

Mr Barnes’s mother wept as the court heard details of the injuries caused by the bullet, which entered his head just above the left ear and passed through his skull.

Mr Barnes died on August 25. Mr Tesfay was arrested seven days later after checking into a hotel in Earls Court under a false name.

Roger Smart, prosecuting, said: "Daniel Tesfay shot at Jordaan Williams intending to kill him or cause serious bodily harm but in fact shot and killed Jonathan Barnes."

He said Mr Tesfay was guilty of murder by way of transferred malice.

Mr Tesfay denies murder as well as a second charge of possessing a firearm with the intent endanger life.

The trial continues.