£20,000 to break silence over James Andre Smartt-Ford gun murder

James Andre Smartt-Ford, 17, was gunned down at a disco at Streatham Ice Rink on 3 February 2007, in front of hundreds of young people.

Although more than a dozen people have been arrested, no one has been charged and Scotland Yard used the third anniversary to offer the reward.

Tonight officers will also hand out leaflets on three estates in Lambeth where they believe the killer may have visited or stayed in the past. The leaflets will include an appeal in connection with the murder, as well as a "gang escape" number for youths who want to get out of crime.

Detective Chief Inspector Gordon Allison, of the Trident gun crime team, said: "Three years have passed since Andre was brutally murdered in front of a significant number of witnesses.

"We want to hear from anyone who may remember something from that night, and ask that those who may not have spoken to us before come forward and help us bring the murderer to justice."

He added: "We know there are people out there who know exactly what happened that night and some may know the reason behind this murder.

"These witnesses have the power to bring an end to this and to take dangerous people off the street. We can provide anonymity for people and witness protection." The case has been hampered by the unwillingness of witnesses to come forward.

The shooting happened shortly before 11pm at the popular Saturday night event, which was attended by about 350 young people.

Andre, a trainee electrician from New Malden, was approached by a black youth in dark clothing, who produced a pistol and fired two shots before disappearing into the crowd.

Andre ran a few metres before collapsing on the ice, and was taken to St George's Hospital in Tooting, where he was pronounced dead. The gun was identified as a converted Baikal pistol but has never been found.

Last year Andre's mother Tracey Ford appealed for information on Crimewatch saying her son's killers had "destroyed a family".

Eighteen people have so far been arrested. Four were bailed pending further enquiries, the rest released with no further action.

Anyone with information should call the police incident room on 020 8247 4554 or Crimestoppers anonymously on 0800 555 111.