The family of a 16-year-old boy, shot dead at an ice rink five weeks ago, have appealed again for witnesses to come forward.
James was shot near the entrance to the venue
James Smartt-Ford's family visited the Streatham rink on Saturday night to repeat their calls for information.
A total of eight people have been arrested and released on police bail.
Det Ch Insp Adnan Qureshi said they had an open mind over the motive for the shooting, which happened during a disco attended by up to 350 people.
Speaking outside the rink he said: "We are following a number of significant inquiries. However, we still need people to come forward."
James was shot near the entrance to the venue at about 2300 GMT on 3 February and managed to stagger onto the ice. He died later in hospital.
DCI Qureshi said he believed potential witnesses may be too afraid to come forward but said he was sure there were people who knew the motive behind the shooting.
"There were a lot of people here. Some were skating, some were on the perimeters when an unknown black male approached from behind... and fired two shots."
The officer said the victim's mother had attended the scene with other family members but was too distressed to talk.
"She is very upset. She has lost a 16-year-old son who was totally innocent."
DCI Qureshi said an incident room had been set up and people with information could contact police there, or ring Crimestoppers anonymously.
James' death was one of three teenage gun murders within a two-week period in south London.
Michael Dosunmu, 15, and Billy Cox, also 15, were both gunned down at their homes in south London.