One of the most senior officers in the Metropolitan Police said it is "a matter of huge regret" that it has taken nearly two decades to bring anyone to justice for the racist killing of Stephen Lawrence.
Today's conviction of Gary Dobson and David Norris for their role in his death comes after an investigation lasting nearly 19 years, during which the force has faced coruscating criticism for the way it handled the probe.
The first investigation into Mr Lawrence's death in April 1993 was lambasted after a public inquiry.
Sir William Macpherson's 1999 report of the inquiry's findings called the standard of command in the vital first few hours after Mr Lawrence's killing "abysmal".
He branded the Met Police institutionally racist, and there were allegations by lawyers representing Mr Lawrence's parents that some officers were influenced by the former drugs baron father of David Norris.
Acting deputy commissioner Cressida Dick said: "It's a matter of huge regret to the Met that it has taken 18 years to get to this point."
She went on: "Every homicide case is incredibly important and we seek to bring the killers to justice. This case, which as you know has taken 18 years to get to this stage, is a unique case, not just for the Met but I think in modern policing.
"Firstly because of the horrible, horrible nature of the racist attack, secondly because it's taken so long to come to court in this way and thirdly because of the public inquiry and the very wide-ranging recommendations that came out of that which have transformed policing.
"We were criticised for the way in which the Met investigated in 1993, we've transformed the way we do investigate homicide and I like to think that where we are now exemplifies how we've changed in terms of the way we investigate."
The Macpherson report criticised several aspects of the initial investigation, including the failure to follow up reports of a red Astra car seen near the scene that night.
It later transpired that three of the passengers had previous convictions for racist attacks and were members of a gang called the Nutty or Nazi Turnout - although they have never been implicated in Mr Lawrence's death.
A number of suspects were identified by anonymous informants in the wake of the killing, but there was a two-week delay in any arrests taking place. The investigation was found to be "grossly understaffed".
No officer gave Mr Lawrence first aid, with the lack of proper training in this respect being "strongly criticised".
Mr and Mrs Lawrence and Mr Lawrence's friend Duwayne Brooks, who was with him when he was killed, were "inadequately, inappropriately and unprofessionally" treated, the inquiry found.
And at one point, an officer named only as Sergeant XX, who was previously seen in a pub with David Norris' father Clifford, was assigned to look after Mr Brooks when he was called to give evidence as part of the private prosecution.
Ms Dick said that the public inquiry was a "turning point" for the force, and that major changes have been made since.
However she admitted that last summer's unrest linked to the shooting of Mark Duggan laid bare problems in the relationship between police and black and ethnic minority communities.
"We've put into place a number of things as a direct result of the public inquiry which allow us both to understand what individuals and families and communities want, to involve them in the policing that they receive and to seek specific advice about particular cultural or religious issues that we might not understand that well.
"That said, clearly the disorders of the summer indicate that there are areas in which we still need to improve some of our community engagement and we're working hard to do that."
She said that the Stephen Lawrence investigation was "an extraordinary case" and added: "I can't think of another investigation that has had anything like that level of scrutiny and effort over the years. It is truly unique."