A teenager accused of stabbing 15-year-old Alan Cartwright to death for his bike wept when he entered the police station because of flowers on the road, a court heard.

Joshua Williams, 18, of Davenant Road, Upper Holloway, was seen “crying hysterically” and carrying a Bible when he was taken to police by his parents, days after the attack on February 27, the Old Bailey was told this week.

Daniel Williams, 27, said his brother was emotional when he entered Islington Police Station because, during the car journey to the police station in the early hours of March 3, he had seen flowers laid for a friend who had died in Pentonville Road.

When questioned on the name of the friend who the flowers were laid for Mr Williams said: “I don’t know.”

He said that Joshua had made no mention of the flowers during the car journey but that he had discovered the fact after his arrest.

He said: “I’ve seen him since. I have visited him in prison.”

Joshua was allegedly caught on CCTV murdering Alan, who was cycling with his friends in Caledonian Road.

Alan was stabbed as a group of three males carried out a “pincer movement” to rob them of their bikes in a seven-second attack caught on shocking CCTV footage, the Old Bailey was told.

He made a desperate attempt to escape after the knife punctured his lung, but collapsed and died a few yards up the road.

Williams says he was elsewhere at the time of the incident and denies murder and conspiracy to rob.

The trial continues.