A teenager has been jailed for the manslaughter of 17-year-old Usaama Ali in Acton.
The 17-year-old had previously pleaded guilty to manslaughter, but had been found not guilty of murder at Isleworth Crown Court on July 25.
At the same court September 9, 2016 he was sentenced to nine years' imprisonment.
A murder investigation was launched after police were called at around 12:50pm on 16 October 2015 to Crown Street in Acton.
Officers found Usaama, who had a stab wound to the heart. The officers, together with two local doctors and other members of the public who had rushed to help him, carried out first aid and tried to save his life.
Usaama was taken to St Mary's Hospital where he was pronounced dead at 2pm that day.
Usaama had gone to a café in Crown Street that day to have breakfast. The court heard from witnesses that at about 11:50am there was an argument outside the café between Usaama and the defendant that culminated with him stabbing Usaama in the chest.
The defendant ran off back down Crown Street, disposing of the knife, and a short time later he disposed of his clothes and a mobile phone that he had been using.
Local officers carried out enquiries in the area and, from the descriptions given by witnesses they recognised the defendant as a possible suspect.
He was arrested later that same evening at his home address in the Catford area.
Detectives used telephone data to piece together communication between the two teenagers in the days leading up to the murder and the court heard evidence that there appeared to have been conversations between them regarding a Segway that Usaama was offering for sale.
The attack happened in October 2015.
Elijah Herry-Gooding 18 of West Street, Erith, was also charged with Usaama's murder - he was found not guilty of both murder and manslaughter.