Emergency services were called to Lavender Hill on Tuesday (October 21) at around 3:26pm.
A teenage boy was found at the scene with stab wounds and was rushed to hospital.
His condition deteriorated and he later died from his injuries in hospital yesterday (October 24).
Police have identified the victim as 19-year-0ld Rinneau Perrineau, known as Ren by his family and friends.
In a statement Ren’s family said he was “loved by many” and would be “dearly missed”.
Rinneau’s family said: “‘Ren was loved by many, he was always around his family.
“He will be dearly missed.”
A murder investigation was opened by Met Police with one person arrested.
Police are making urgent enquiries and the force has confirmed that this 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 are urging anyone in the Beauchamp Road area between 3:20pm and 3:30pm on Tuesday (October 21) to come forward by contacting 101, quoting crime reference 4781/21OCT.
Information can also be reported anonymously by contacting Crimestoppers on 0800 555 111.
