Police and paramedics were called to Lavender Hill at around 3.30pm on October 21.
Rinneau Perrineau, 19, known by his nickname Ren, was taken to hospital with in a life-threatening condition.
Despite fighting for his life, Rinneau’s condition deteriorated and he died yesterday (October 24).
His family are being supported by specially-trained officers.
In a statement, Rinneau’s family said: “Ren was loved by many, he was always around his family. He will be dearly missed.”
An arrest has been made and detectives continuing their investigation.
It is believed to be an isolated incident.
Acting Borough Commander Amanda Mawhinney, who leads policing in the area, said: “Our thoughts are with the victim’s loved ones at this terrible time.
“This was a shocking crime committed in broad daylight. A teenager’s life was taken, and his family and friends have suffered an irrevocable loss.
“Our officers are making every effort to bring those responsible to justice.
“Residents may notice a police presence around the scene of the crime, as patrols have been stepped up in the local area.
Officers believe there are a number of witnesses yet to come forward and are urging anyone who was in Beauchamp Road between 15:20hrs and 15:30hrs on Tuesday afternoon (October 21) to call 101, quoting crime reference 4781/21OCT.
Anyone who wishes to remain anonymous can speak to Crimestoppers on 0800 555 111.
