A 16-year-old boy murdered teenager Mustafa Momand when he “plunged” a large kitchen knife into his chest, a jury decided.

The 17-year-old who grew up in Brighton was stabbed to death in broad daylight over a drug debt while walking to the city's train station on October 5.

The jury found the attacker, who cannot be named for legal reasons, guilty of murder this morning.

He crossed paths with Mustafa and “rammed” the knife into his chest with a “force so severe” that it broke through his breast bone and severed one of his pulmonary arteries.

Mustafa “ran for his life” up Queen’s Road for around 150 metres before collapsing where people tried desperately to save his life.

He was taken to the Royal Sussex County Hospital where surgeons performed emergency surgery by opening up his chest and sewing up his pulmonary artery.

They also gave him 16 litres of blood but Mustafa was pronounced dead at 6.40pm. The stabbing happened just before 5pm.

The Argus: Mustafa Momand was pronounced dead at the Royal Sussex County Hospital on the same day he was stabbedMustafa Momand was pronounced dead at the Royal Sussex County Hospital on the same day he was stabbed (Image: Sussex Police)

Meanwhile, the attacker fled through central Brighton to Bevendean where police arrested him initially on suspicion of attempted murder. They further arrested him on suspicion of murder when they learnt that Mustafa was dead.

He discarded his balaclava and a glove he wore during the attack in a wheelie bin in Bevendean Crescent. His knife was never found.

Blood was found on his boxer shorts where he tucked the knife, his clothing and the soles of his shoes from where Mustafa was “squirting” out blood as he desperately tried to escape.

The attacker, from Southwick, told the jury he left the house after an argument with his parents and got the first train he could which happened to be Brighton. He said he hid his face because of being self-conscious about his acne.

The Argus: Tributes at the scene for Mustafa MomandTributes at the scene for Mustafa Momand (Image: Andrew Gardner/The Argus)

The boy claimed that he took a knife to self-harm, not to hurt anyone but happened to bump into Mustafa. He said Mustafa had threatened to stab him previously so he wanted to scare him.

The boy claimed that Mustafa “skipped into the knife”. The boy also said he only wore one glove, the one he used to hold the knife, because the other one was damp as his mother had put it in the wash.

Mustafa moved to social care in Bevendean and eventually South Croydon in April last year where his family thought he might be away from trouble.

The court heard that he had a £20,000 drug debt to Zakaria Deghayes, also known as Gotti or Zico.

Nathan Rasiah KC, prosecuting, said the defendant “knew that Mustafa Momand was a target” because of this and stabbed him “on behalf of Gotti”.

The Argus: The boy was arrested in BevendeanThe boy was arrested in Bevendean (Image: Sussex Police)

Mustafa was leaving Brighton Magistrates’ Court for drug-related offences the day he was murdered.

Less than two weeks before he died, Mustafa was surrounded by a group of boys at Churchill Square who said they would not beat him up as he was with his mum Suraya.

Mustafa referred to them as “Gotti’s lil army” on a message to a friend.

The attacker denied murdering Mustafa as well as two other separate incidents in July and August 2023 of threatening another with a bladed article and threatening with an offensive weapon.

The unanimous jury found the teenager was guilty of threats with a blade, not guilty of threats with an offensive weapon and guilty of murder.

He will be sentenced on May 2.