An Afghan asylum seeker who had previously been convicted of murder in Serbia has been found guilty of killing a young man in a row over an e-scooter.

Lawangeen Abdulrahimzai killed 21-year-old Thomas Roberts outside a Subway sandwich shop in Bournemouth, Dorset, in March, last year.

Abdulrahimzai, 21, had admitted manslaughter but the jury at Salisbury Crown Court took 12 hours to find him guilty of murder on Monday with a majority verdict.

After delivering their verdict, the jury heard Abdulrahimzai had previously been convicted of murder following a trial in Serbia and had been sentenced to 20 years in prison in his absence.

Mr Roberts’ family described his death as “violent and unnecessary” and issued a warning not to carry knives “so other families do not suffer in the way we as a family are suffering now”.

Mr Roberts was acting as the “peacemaker” in the early hours of March 12, 2022, after his friend James Medway got into an argument with Abdulrahimzai.

Mr Medway wanted to take an e-scooter Abdulrahimzai had claimed for himself and left propped against the window of the shop in Old Christchurch Road.

The confrontation, which lasted only 24 seconds, saw Mr Roberts slap Abdulrahimzai in the face.

Abdulrahimzai then revealed the knife he had hidden between the two pairs of trousers he was wearing and stabbed Mr Roberts twice before running away into nearby woodland.

He buried the knife in the woods before burning the trousers, jacket, and Afghan flag he was wearing as a scarf.

However, he dropped his mobile phone as he fled and it was traced to his home address.

In the months before the incident, Abdulrahimzai shared pictures of himself posing with a knife about 10in long on the social media and video sharing app TikTok.

He had been seen carrying a knife by his foster parent, who had warned him not to, and had also been warned by police and social workers of the dangers of carrying a knife.

Abdulrahimzai told the court that he carried a knife because he was “fearing” for his life because there were people from Afghanistan who wanted to kill him, and he had also had death threats in Bournemouth.

The defendant said he posted photos of his knife on TikTok to get followers from “people out there liking knives”.

Abdulrahimzai, who lived in Poole at the time of the offence, arrived in the UK in December 2019, and told the authorities he was 16 when he was arrested, but the court has since determined that he is now 21.

In his defence, Abdulrahimzai said he had no intention to kill or cause really serious harm to Mr Roberts – he “acted instinctively”, said he “feared for his life”, and felt he had to defend himself.

The court heard his parents had been killed and he had been tortured by the Taliban so he carried a knife for his own protection.

Detective Chief Inspector Simon Huxter of Dorset Police said: “First and foremost our thoughts are with the family and loved ones of Thomas Roberts.

“This case serves as another reminder of the truly devastating consequences of knife crime.”

The force also confirmed it had not been aware of Abdulrahimzai’s previous convictions before his arrest for Mr Roberts’ murder.

In a statement Mr Roberts’ family said: “The family of Thomas Roberts cannot describe the loss of their son, brother, partner, friend in the tragic circumstances of his violent and unnecessary death.

“He had a potentially fulfilling future to look forward to, whether that be in his profession of precision engineer or his potential in the military.

“Thomas was a normal kind person, who had enjoyed life. On the night of his tragic death, he was in town with friends having a good time when he was suddenly involved in an incident involving a large knife that cost him his life.

“The family would like this to be a warning to everyone not to carry knives so other families do not suffer in the way we as a family are suffering now.”

Abdulrahimzai will be sentenced at Salisbury Crown Court on Wednesday.