Twenty years ago, 10-year-old schoolboy Damilola Taylor was stabbed in the leg and left to die in a south London stairwell. It took six years and three trials for brothers Danny and Ricky Preddie to be convicted of manslaughter. They were aged 12 and 13 at the time of the killing.
Police say the investigation was hampered by a wall of silence from the local community in Peckham as well as a lack of experience dealing with children in gangs. So what has changed since the shocking killing?
It was a cold and wet evening on 27 November 2000, recalled Rod Jarman, who at the time was the Metropolitan Police's Borough Commander of Southwark.
He had just arrived home from work when colleagues called him to say a boy had been found bleeding to death in a concrete stairwell in Peckham. Damilola had been stabbed in the leg with broken glass.
The scene was even worse than it appeared in pictures that were later splashed on the front pages of the national newspapers, Mr Jarman said.
The Metropolitan Police knew its response to Damilola's death would be under intense scrutiny following criticism of its investigation into the killing of another black boy, Stephen Lawrence, in 1993.
While colleagues hunted Damilola's killers, Mr Jarman's role was to try to calm the fears of local residents and understand the wider context of a crime that shocked the UK.
Brought up by their single mother in Peckham, Danny and Rickie Preddie were members of the Young Peckham Boys street gang, which terrorised the North Peckham Estate at the time of Damilola's death.
It soon became clear local officers had underestimated the problems on the estate and had moved patrols away from the area.