Police are urging drivers who may have passed close to the scene in Victoria Road on Tuesday last week to come forward with any dashboard camera footage they have recorded.
Officers from the Homicide and Major Crime Command are visiting the area around West Mead and Angus Drive between 8pm and 10pm tonight.
Osam Shisane, from Ruislip, was killed after being stabbed multiple times. He eventually died in hospital last Friday.
Detective Chief Inspector Paul Healy, said: "I am particularly keen to hear from anyone who was driving in the area of Victoria Road between 8.30pm and 9.30pm on the night of Osman's murder and may have dash cam footage that can assist us with our enquiries.
"I also appeal directly to those people in the community who know what took place, or recorded the incident on their mobile phones to get in touch if you haven't done so already, and help us give Osman's family the justice they deserve."
He added: "Efforts continue to establish exactly what happened in the lead up to this violent attack in which Osman suffered several stab wounds.”
Police were called shortly after 9pm on Tuesday, 15 May to “reports of a man suffering from stab injuries on Victoria Road”.
The London Ambulance Service and London's Air Ambulance also attended.
Mr Shidane was taken to a central London hospital in a critical condition. He died at 5.16pm on Friday, 18 May.
His next of kin have been informed.
A post-mortem examination held on Saturday, 19 May gave cause of death as multiple stab wounds.
An incident room has been opened by detectives from the Homicide and Major Crime Command. Enquiries continue.
Anyone with information is asked to contact the incident room on 0208 358 0200 or Crimestoppers anonymously on 0800 555 111.
- A 16-year-old boy was charged with murder on Saturday, 19 May.
- A 15-year-old girl who was arrested on Wednesday, 16 May on suspicion of assisting an offender has been released on police bail.