Emadh Miah, 18, chased and lunged at Ghulam Sadiq, 18, with the “very large and deadly knife”, in Leytonstone, east London, “metres away” from the victim’s home, on August 6, 2022.

Miah, from Solihull, West Midlands, was found guilty of Mr Sadiq’s murder during a trial at the Old Bailey in April this year.

At the sentencing at Lewes Crown Court on Tuesday, the court heard how Miah had carried out the “planned attack” by buying the weapon online using someone else’s ID because he was underage, before travelling to London with his mother to visit his grandfather.

During this visit he rented a bike, and then hid his identity by wearing a mask, gloves and hood when he attacked Mr Sadiq, which was captured on CCTV.

Miah was on bail at the time for attacking a 16-year-old boy with a hammer on March 21, 2021.

Defending, James Wood KC said Miah was visiting his grandfather ahead of the sentencing for that offence, and that the long wait for the case proceedings was a “stressing factor”.

In a statement read out in court from Mr Sadiq’s mother, Khalida Parveen, she recalled the day she saw her son lying in a pool of blood outside a pizza shop.

Mr Sadiq had just “popped out” to get some food for a barbecue the family were going to have that day in the garden.

“There are no words that can describe my loss and pain,” the statement said.

“That wretched day is unforgettable.”

Ms Parveen added: “I’m here today for justice, we have lost our world, please don’t let him do the same to anyone else.

“I’m haunted by the recurring nightmare of the horror Ghulam suffered. I blame myself for not being able to protect my child from such a cold-blooded individual.”

The mother-of-two said she and her younger son have kept Mr Sadiq’s clothing, and items such as a handwritten yellow note saying “don’t worry, I’ll clean my room when I get back”.

The teenager was described as “very popular, passionate and great fun”, and always coming up with business ideas, his latest being a premium platform for cleaning trainers.

The court also heard that Miah has a number of mental health difficulties, including post traumatic stress disorder from violent incidents of bullying against him, and conduct dissocial disorder. He also has mild autism.

In a statement written by the defendant, read to the court, he said: “I’m sorry for what I have done, I didn’t mean for it to happen. I’m not good at writing so I will ask my mum to write out what I want to say, but for Ghulam’s family I’m sorry for causing you so much pain.”

Miah’s family also wrote in a statement about their “devastation” at their son’s actions.

Judge Christine Laing KC sentenced Miah to life in prison with a minimum term of 19 years, reduced to 18 years and 45 days due to 320 days already served in custody.

Concurrent sentences were also given for the hammer attack and possession of a hammer and bladed article.

Judge Laing KC said while she was sure the “shocking offence” was a planned attack, she could not be sure Miah intended to kill Mr Sadiq.

“Although I have no doubt you intended to cause the maximum harm to Ghulam Sadiq, I will give you benefit of the doubt you didn’t intend to kill him,” she said.

While taking into account his autism and mental health issues, Judge Laing KC added: “I’m quite satisfied he knew what he was doing.”

Previously, at the end of the trial, Judge Laing KC had spoken about the “shocking” availability of dangerous weapons online, urging jurors to write to their MPs.

At the sentencing, she highlighted the “desperate need” to stop young men and teenagers obtaining these weapons and using them against other teenagers.