Glasgow added: "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."
The court heard how the spate of robberies began at 10.30pm in Maida Vale when they approached Nazmul Chowdhury and demanded he handed over his belongings.
After spotting a knife he fled, but they chased him and mounted the pavement, and as he tried to board a bus to escape Gilmaney stabbed him in the back.
An hour later in Paddington the pair attacked Venezuelan Ehimer Fierro-Berbesi and his elderly aunt Ana Fierro-Berbesi who were sitting outside their home, it was said.
They threatened them with knives and stole jewellery and money, and allegedly stabbed Fierro-Berbesi in the stomach.
Seconds later, they confronted Samad. At first the pair rode off but turned around and shouted at him, jurors heard.
Glasgow told jurors that Samad had been confronted by the teenagers in St Mary's Terrace, in Paddington, and handed them something from his pocket.
He gave them something else but Gilmaney allegedly got off the scooter and stabbed him in the chest.
Glasgow said: "Mr Samad managed to stagger the short distance back to where his family lived but he collapsed at the door. His parents, who heard his cries, found him bleeding to death outside their home."
He died later in hospital having suffered a devastating wound to the heart.
As the emergency services rushed to help and "tried to comfort his traumatised family", the moped muggers "completely unmoved by what they had just done, prowled the streets looking for another target", the court heard.
Samad, a Westminster University economics graduate, worked for the Covent Garden Dragon Trust, a charity which helped young Londoner's improve their IT skills.
A few minutes later they tried to rob Joseph Denby on Golborne Road, and when he showed his phone was an old Nokia, they demanded his wallet but he escaped.
Two other victims were robbed of their belongings before the pair returned to Maida Vale to offload their stolen goods - including Samad's iPhone and some foreign currency - to a man in a high-rise.
About 20 minutes later, at 1.30am, they tried to rob Graipich Vudto in Porchester Road, and Gilmaney stabbed him in the stomach after he refused to let go of his phone, before speeding off.
Minutes later, Gilmaney stabbed Silverio Pina in the arm on Princess Square, and at 1.50am, they snatched a phone out of the hand of Natevan Casinova at the junction of Portobello Road and Pembridge Road.
Just after 2am, the court heard how they approached Shemiqua Moore-Dingwall and her friend Matthew Calonga on Cricklewood Lane.
She handed over her bag, but Gilmaney punched her in the face and just five minutes later they demanded Nelson Aparicio hand over his phone and wallet, only to be stabbed in the stomach.
As the number of casualties mounted, police were alerted and scoured the area for the culprits.
Glasgow said the defendants tried to escape but were arrested after a police chase.
Their pockets were stuffed with stolen valuables and CCTV captured them in the act of riding around and attacking helpless strangers, the Old Bailey heard.
Samad's mobile phone was among stolen items sold on the same night but recovered during a police search of the man's flat off Harrow Road, the court heard.
Gilmaney, of Maida Vale, west London, admits manslaughter, three counts of attempted robbery, six counts of robbery, four counts of wounding with intent, and one count of theft.
The teenager admits theft, three counts of attempted robbery and six counts of robbery, but denies four counts of wounding with intent.
Both defendants deny murder and the trial continues.
