A teenage “foot soldier” who stabbed a Croydon student to death over his £20,000 drug debt has been jailed for life. 

Armin Mehdikhani-Sarvejahani, 16, armed himself with a kitchen knife then shouted “I’m going to f***ing get you” before stabbing 17-year-old Mustafa Momand to death in Brighton on October 5 last year. 

The killer then smiled as he was arrested for murder. 

A-level business and law student Mustafa had travelled to Brighton from Croydon for a court appearance. 

But as he was walking away form the court he bumped into Mehdikhani-Sarvejahani. 

Lewes Crown Court heard on Thursday how Mustafa spent his dying moments running away in fear after he was knifed through the breast bone on Queens Road.   

He then ran for 150 metres before he staggered and collapsed while his attacker yelled after him. 

Judge Mr Justice Constable KC said Mustafa was trying to turn his life around from being a “minor pawn in the terrible drug business which destroys so many lives”. 

Your Local Guardian: Mustafa Momand Mustafa Momand (Image: PA)The trial heard how Mustafa had racked up a £20,000 shared drug debt and that his parents had tried to save him from drug dealing and debts, and even begged the police to send him to prison. 

Sentencing Mehdikhani-Sarvejahani, Mr Justice Constable said: “(Mustafa Momand) was a brave young man who took the decision to try and leave the drug world behind him with his parents’ support, but this meant leaving this so-called unpaid debt. 

“I have no doubt that you were tasked, as an expendable foot soldier, with inflicting lethal punishment on Mustafa.” 

He added: “This tragic case serves as a stark reminder of the very real dangers that await young people who get involved in dealing drugs, of the appalling way in which young lives spiral quickly into effective servitude for the financial benefit of others and become treated as expendable, and most clearly, of the devastating consequences of ever more frequent knife crime.” 

The judge sentenced the defendant to a minimum of 17 years in prison for what he described as a planned and premeditated attack. 

In CCTV footage he is seen wearing a balaclava and putting a single glove on his right hand in the moments before stabbing Mustafa. 

The judge also said his evidence given during the trial that it was an accident was “untrue and cowardly”. 

Your Local Guardian: Mehdikhani-Sarvejahan, described as an expendable foot soldierMehdikhani-Sarvejahan, described as an expendable foot soldier (Image: PA)

During the trial, jurors heard how Mustafa had told his mother Suraya Momand he “regretted everything” and talked about going to college to study law to help exploited children. 

He had moved to the UK from Afghanistan with his family in 2009 when he was three years old, and in late 2021 his mother found cannabis in his room and suspected he was using or dealing drugs. 

When Mustafa turned 16, things “got worse” and his behaviour changed, his parents found weapons in his pockets and he went missing for days on occasion, coming back with valuable items or injuries, the court heard. 

Jurors were told that in November 2022 Mustafa told his father he was in debt and needed £8,000 or “they will kill me”. 

The teenager “cried and pleaded” until his father managed to give him some money, the court heard. 

His father got him a job in a chicken shop, and he would stand outside for hours while Mustafa worked as he was scared the people who he owed money to would find him there. 

Eventually, Mustafa was moved out of the area to a care home in Croydon in April 2023. 

While living there he registered to begin a two-year A-level course in business and law and went shopping with his mother for new clothes for college in Brighton on September 23. 

On the trip to Churchill shopping centre, Mustafa was shocked and “shaken” to bump into someone and was surrounded by a group of young men who let him go, because he was with his mother. 

His mother recalled a phone call Mustafa received in the car afterwards to tell him to run. 

Less than two weeks, later on October 5, Mustafa travelled from Croydon to Brighton Magistrates’ Court for an appearance in relation to drug offences. 

He left court alone and was walking in the direction of Brighton train station, on Queens Road. 

The pair were seen coming into contact on bus CCTV footage at about 5pm, when the city centre was busy, and lots of people saw the fatal attack. 

Mehdikhani-Sarvejahani was also found guilty and sentenced over a separate incident in 2023 of threatening another person with a bladed article. He was cleared of a similar offence. 

During the trial he was granted anonymity because he was under 18-years old, but the judge lifted the reporting restriction at sentencing after applications by the press.