An image of the 16-year-old boy who was murdered in Wandsworth on Monday (February 17) has been released by the police.
To date nine people have been arrested in connection with the death of Peter Hagan, who was found in a block of flats. One of those taken into custody, an unidentified 21-year-old male, remains in a south London police station on suspicion of murder.
The remaining suspects have been bailed until March pending further enquiries.
The murdered teen was discovered at 1.30am on a ground floor stairwell in Albon House in Neville Gill Close, Wandsworth, southwest London.
Officers are appealing for witnesses and our interested in a tracking down a group of "five to eight males" seen running from the murder scene.
DCI Nick Scola, of the Homicide and Serious Crime Command, said: "I believe the victim had attended a party in Albon House.
"I need to trace everyone at that party, and in particular I am appealing for any information about a group of between five and eight males seen running from the scene into the surrounding streets and possibly through King George's Park."
Any witnesses or anyone with information should call the incident room on 020 8721 4005. To remain anonymous call Crimestoppers on 0800 555 111.