Lathaniel Burrell was found injured in Paradise Road just after 3.20pm on March 4.
Officers and London Ambulance Service crews attended, however, he was pronounced dead shortly after.
Police arrested 32-year-old Omar Prempeh who was charged with murder on March 8.
The following day on March 9 police arrested a 17-year-old boy on suspicion of murder.
A 40-year-old woman was also arrested on suspicion of assisting an offender and for possession with intent to supply of Class A and B drugs.
She has been bailed pending investigation.
Prempeh is due to appear at the Old Bailey on March 12.
Lathaniel’s family continue to be supported by specialist officers.
Det Chf Insp Sarah Lee said: “Though we have made progress with this investigation, we continue to appeal for anyone with information about Lathaniel’s murder to please come forward and speak to us.
“We’re particularly appealing to anyone who was in the area of Paradise Road on Tuesday, 4 March. I’d also appeal to anyone with doorbell or dashcam footage around this time to come forward.
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“Our priority remains tracking down those responsible for killing Lathaniel and bring them to justice.”
If you have any information which may help police with their investigation, please call 101 with the reference 4116/4MAR.
You can also contact the independent charity Crimestoppers on 0800 555 111 to remain anonymous.
