A 19 year old Eniola Aluko died on Friday after sustaining gunshot wounds to the neck and chest.
The Police said they were called to the scene, a car park on Hartville Road, just before 5pm.
Mr Eniola Aluko was found with critical injuries and died at the scene a short while later after armed police, local officers, the London Ambulance service and air ambulance all attended.
A post-mortem examination held on Sunday revealed that he died from of a single gunshot wound to the neck and chest.
However, the Police said on Sunday that they had made a fifth arrest overEniola Aluko’s death. An 18-year-old man has been arrested on suspicion of murder and remains in police custody.
Four teenagers – one 17-year-old boy, two 16-year-old boys and one 17-year-old girl – who were arrested on Friday have all been bailed until July pending further enquiries.
The Detective Inspector John Marriott, said: “I am continuing to appeal for anyone who was in the area at the time, who saw or heard anything suspicious to contact police.
“The shooting took place not far from Plumstead Railway Station and I would urge anyone who was commuting to or from this station to come forward.
“It was also sunny at the time and a number of people would have been enjoying the weather in the area of Plumstead Gardens; I need you to come forward.
“Although we have now made five arrests I am continuing to ask for your help to progress this investigation.”