On an April evening in 1993, the 18-year-old A-level student and his friend Duwayne Brooks were rushing to catch a bus home in the south-east London suburb of Eltham when they were confronted by a gang of white youths. The gang stabbed Stephen as Duwayne watched in paralysed silence, before he was chased off by the young men.
Driven by fear and adrenaline, Stephen managed to scramble free as Duwayne urged him to "just run". But he was bleeding profusely and died 200 yards away. The police investigation, or rather lack of it, led to a public inquiry that put the police and British justice system on trial.
On the night of Stephen's killing, a passing off-duty officer was at the scene within minutes. But, despite numerous tip-offs within hours of the murder, officers adopted a lacklustre approach. Three months later, charges against two youths were dropped because the Crown Prosecution service insisted that there was insufficient evidence to proceed.
Eventually, a senior Scotland Yard officer, Superintendent Roderick Barker, was drafted in to conduct an internal inquiry into the investigation. He reported that the probe had "progressed satisfactorily and all lines of inquiry had been correctly pursued".
But as evidence mounted against the police, both in terms of their handling of the investigation and their treatment of Stephen's parents, Neville and Doreen, it became clear that a more far-reaching investigation would be required. The Lawrence family began a private prosecution, which collapsed when identification evidence against three youths was ruled inadmissible, and a second internal inquiry, led by Kent Police, was ordered by the Police Complaints Authority.
An inquest into Stephen's death in February 1997 concluded the death was an "unlawful killing". The five main suspects - Jamie and Neil Acourt, Gary Dobson, Luke Knight and David Norris - refused to answer any questions but were publicly named in the media.
By the time the Kent force reported back its findings, concluding the police had been well-organised and effective, and that there was no evidence of racist conduct, a public inquiry was already in the offing under the chairmanship of Sir William Macpherson.
Shocking evidence before the inquiry included secret police tape of the suspects brandishing knives and expressing violent racist views as well as Sir Paul Condon, then the Metropolitan Police commissioner, apologising for "our failure" to Mr and Mrs Lawrence. Again the five suspects were evasive, continuing to protest their innocence. As they emerged from the inquiry, they reacted angrily to being pelted by onlookers in an iconic image of its time.
In February 1999, Sir William's report offered 70 recommendations to break down institutional racism and Prime Minister Tony Blair promised to implement radical reform.
Over the years many reports of new evidence and potential breakthroughs have surfaced, but none has led to anything. More than three years after the inquiry David Norris, then 26, and Neil Acourt, 27 were sentenced to 18 months in prison for assaulting an off-duty black policeman in the same road where Stephen was stabbed to death almost a decade earlier.