The 17-year-old teenage killer, who stabbed his rival with a red Ninja sword while his victim was under the influence of laughing gas, faces life in prison.

A 17-year-old killer who stabbed a rival to death with a red Ninja sword he bought from a popular online knife site faces life in prison.

Victim Rahaan Amin, 16, was under laughing gas at West Ham Park, east London, when the masked killer, who cannot be named, plunged the weapon into his chest before hiding the sword in a nearby tree and flee on his bike.

He collapsed moaning: “Allah, help” as an air ambulance arrived at the scene on July 9 last year.

Doctors attempted to staple Rahaan's heart in the park, but he died the next day in hospital.

Police found a Snapchat photo the killer had sent to a friend before the stabbing, showing nine knives lined up on his bed, including the Ninja sword.

He bought the deadly weapons through online knife site DNA Leisure using the name and passport of a friend's father.

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The killer denied murder but was today found guilty by an Old Bailey jury after more than 18 hours of deliberation.

Rahaan's family members wiped away tears behind their veils as the verdict was announced. The killer turned to them and smiled as he was led to the cells.

Judge Alexia Durran told the jury: “Some of you may have read in the newspapers that knife crime has increased by 20 per cent.

“Now you may know why you read these statistics.”

Prosecutor Kate Lumsdon, KC, earlier told the court the defendant and victim had had an ongoing feud in the months leading up to the murder.

Rahaan had previously been arrested on suspicion of being involved in the stabbing of one of the accused's friends.

The prosecutor said: “On Sunday afternoon July 9, 2023, Rahaan Ahmed Amin was at West Ham Park with friends.

“Around 5:30 p.m., a young person, with his face covered, entered the park on a bicycle. He approached the group of friends on bicycles.

“He took out a long red knife from his pants and stabbed Rahaan Ahmed Amin in the chest.

'Rahaan collapsed. The paramedics were called. He was taken to hospital. There was nothing to do. He died the next day.'

The killer got back on his bike and rode away. A friend was heard shouting “Why did you do that?” against him as they fled, the court heard.

He threw the Canada Goose vest he was wearing at a friend's house, but police recovered it and found traces of Rahaan's blood on it.

Jurors were told few friends at the park wanted to tell police what happened.

The 17-year-old from Forest Gate admitted stabbing Rahaan – but claimed he acted in self-defence.

He was found guilty of murder and will be sentenced on September 7 when he faces an inevitable life sentence.

The judge will then decide whether he should be identified.