Two teenage robbers likened to “21st-century highwaymen” have been found guilty of stabbing a charity youth worker to death during a violent spree on a moped.

Nathan Gilmaney, 19, and Troy Thomas, 18, tried to rob as many people as possible, leaving a trail of destruction on 16 October last year.

They killed Abdul Samad for his iPhone and little more than “aggression and bloodlust” as they swept across north-west London on a scooter.

Samad, 28, handed over valuables when confronted by the teenagers in Paddington. But Gilmaney got off his moped and stabbed him in the chest.

The victim staggered back to his home and collapsed on the doorstep in front of his parents.

The court heard the defendants were unmoved by the plight of Samad and his family, and prowled the streets for their next target minutes later.

The pair, from Maida Vale, north-west London, were convicted of murder following a trial at the Old Bailey.

During the trial, Oliver Glasgow QC, prosecuting, said they were “highwaymen of the 21st century who thought they had the right to threaten and rob whoever they found, who attacked their targets in a brazen and shocking manner, and who stabbed their victims often for no reason other than simple aggression and bloodlust”.

“They hoped to steal wallets and valuables from their victims and, where possible, they intended to take their victims’ mobile phones, which they knew they could quickly sell for cash,” he told jurors.

“By the end of their four-hour spree of violence, they had committed nine knifepoint robberies, they had gratuitously stabbed four of their defenceless victims, and they had killed Abdul Samad, a 28-year-old man whose job as a charity youth worker had seen him devote his time to helping the very sort of young men who took his life.”

As the number of casualties mounted, police scoured the area and, after a chase, arrested the culprits, whose pockets were stuffed with stolen valuables. CCTV captured them riding around and attacking strangers.

Samad’s mobile phone was among stolen items sold on the same night, but recovered during a police search of a flat off Harrow Road, the court heard.

Thomas admitted robbing the victims, but denied responsibility for the violence. Gilmaney had pleaded guilty to the robberies and violence, but both defendants denied murder.

Gilmaney had admitted manslaughter, but claimed he did not intend really serious harm.

The jury deliberated for more than 19 hours before returning the guilty verdicts.

They rejected Thomas’s claim not to have been involved in the violence and found him guilty of unlawful wounding and three counts of wounding with intent.

Relatives of the victim wept in court as both defendants were found guilty of murder.

The judge, Richard Marks QC, remanded the teenagers in custody to be sentenced on 15 June.

DI Shaun Fitzgerald of Scotland Yard said: “The teenagers believed they had the right to threaten and rob wherever they wanted, often stabbing their victims for no reason at all but to prove they could.”

Samad’s mother, Layla Begum, said: “The death of my son has absolutely broken my husband, my eldest son, my entire family and me.

“I will never be able to get over losing a son. I feel like Abdul’s death has caused a hole in my heart, and a vital organ of my body is missing. I often feel like a dead woman walking around my home.”