Two teenage moped riders have each been jailed for more than 20 years after stabbing a man to death during a violent robbery.

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 28-year-old charity youth worker Abdul Samad for his iPhone and little more than “aggression and blood lust” as they swept across west London on a scooter.

At the Old Bailey on Friday Gilmaney was sentenced to life imprisonment with a minimum of 27 years and Thomas detained with a minimum of 22 years.

They chatted to each other at times during the hearing, smiling and laughing together in the dock.

Nathan Gilmaney. Photograph: Met/PA

The public gallery was packed, and statements were read on behalf of Samad’s mother and girlfriend. Gilmaney shouted obscenities after the sentence was passed and the public gallery had to be cleared after repeated outbursts.

The judge, Richard Marks QC, said: “Abdul Samad was an outstanding young man in his 20s, engaged to be married and had his whole life ahead of him.

“Your wicked stabbing of him has left his family understandably utterly devastated.”

Gilmaney knifed the charity worker in the chest in an attempt to get the pin for his phone, the judge said.

After being stabbed, Samad collapsed on his doorstep in front of his parents while the robbers prowled the streets for their next victim. Their spree of violence was committed over four hours in north-west London and involved nine knifepoint robberies.

Troy Thomas. Photograph: Met/PA

Gilmaney stabbed four other victims, who all survived, and admitted that he attacked one man because he was angry he had tried to run away.

The judge described CCTV footage of the crimes as “chilling”.

Thomas and Gilmaney were arrested following a police chase, their pockets stuffed with stolen valuables. Thomas admitted robbing the victims but denied responsibility for the violence while Gilmaney pleaded guilty to the robberies and violence.

The pair, from Maida Vale, west London, were found guilty of murder.

Michael Turner QC, representing Thomas, said he was acting as a getaway driver and had “no intention to kill”. “He was not the wielder of any weapon,” he added.

Gilmaney’s barrister, Dexter Dias QC, said he has ADHD and an IQ of “barely 60”. He has a number of previous convictions, including robbery and drugs offences.

Thomas has multiple convictions for other offences and was on bail at the time of the robberies.