At least 11 potential leads went unchecked, according to the detectives examining the original Metropolitan Police inquiry into the stabbing of Stephen Lawrence four years ago. Potential witnesses and possibly vital evidence were ignored, and the investigation reveals a catalogue of lost opportunities and failures by Scotland Yard.
A preliminary report by the independent Police Complaints Authority is a damning indictment of the inquiry into the racist murder of Stephen, 18, who was stabbed to death at a bus stop near his home in Eltham, south- east London, by a gang of white youths in April 1993.
It concludes that there is "evidence of significant weaknesses, omissions and lost opportunities during the first murder inquiry". And it adds that the "serious shortcomings" were only uncovered because of the tenacity of Stephen's mother and father, Doreen and Neville, who brought a unsuccessful private prosecution and lobbied the Government.
Additionally, because an internal police inquiry failed to spot the earlier mistakes "subsequent attempts to solve the crime have been hampered".
Also, despite identifying 11 "potentially fruitful lines of inquiry which have not yet been properly followed up", the PCA believes it is increasingly unlikely that the killers will ever be jailed as leads grow cold.
The unusual decision to publish the full details of the PCA findings, based on an inquiry carried out by detectives from Kent police force, were made on the order of Jack Straw, the Home Secretary. They will be submitted as evidence to the judicial inquiry into the murder which is due to being in February.
The inquiry was set up after five white youths were branded "murderers" by a national newspaper following their refusal to give evidence at an inquest in February which found that Stephen had been unlawfully killed during an unprovoked racist attack.
In one of the few positive points contained in yesterday's report, the PCA found no evidence of any racist conduct by officers involved in the investigation, which they said was well resourced. Detectives have been accused of giving the case low priority because Stephen was black.
However, the vast bulk of the findings are a scathing attack on the work of Scotland Yard. Among the mistakes were:
Several important "anonymous" informers were never identified by the Metropolitan police and further questioned. However, the Kent officers were able to discover their names.
Evidence about the identity of possible suspects was available early on, yet the police failed to arrest anyone and therefore lost the chance to obtain forensic evidence.
The PCA report demolishes police claims that their attempts to track down Stephen's killers were hampered by a "wall of silence". It found "considerable evidence" that the people of Eltham had come forward with valuable information.
A key witness withdrew his co-operation because of the way he was handled by detectives, and identification evidence was not properly analysed which may have resulted in at least one of the killers remaining undetected.
Sir Paul Condon, Commissioner of the Metropolitan Police, said yesterday that he accepted the main findings of the report and apologised to the Lawrence family. He added that lessons had been learnt.