A teenager who was murdered after a confrontation with three men on mopeds, has been named as Ethan Nedd-Bruce.
The 18-year-old from Charlton was found with stab injuries outside a party at a flat in Greenwich, south-east London, on Monday and was pronounced at about 22:00 BST.
Police initially thought he had been stabbed to death.
However, a post-mortem examination gave the cause of death as a gun-shot wound, the Metropolitan Police said.
Mr Nedd-Bruce was found collapsed on the Flamsteed Estate.
Det Ch Insp Richard Leonard said: “Ethan was a young man who has been killed in very violent circumstances, leaving his family utterly bereft.”
He added that several people reported the victim get into an argument with a group of men but urged more people to come forward.
“Two men made off from the scene on a motorbike – a rider and a pillion passenger.
“I need anyone who may have information that could assist us to make contact as quickly as possible.”
No arrests have been made.