FROM the beginning, Norris and Dobson made up two out of the five main suspects in the police investigation - but a host of failings meant chances to bring them to justice were missed.

Despite numerous tip-offs giving the same names in the first few days, there were no arrests and no searches made, meaning police missed crucial opportunities to seize forensic evidence.

When surveillance was made of the suspects, it was, according to the Macpherson inquiry report, marred by "inefficiency and incompetence".

A key failing was not to share, or act on the photographs that were taken. A snap of Dobson and Norris together at Bournbrook Road, Eltham, was not made available to Detective Sergeant Thompson when he interviewed Dobson.

Dobson, in that first interview, denied knowing Norris at all - and DS Thompson was unable to use that photograph to challenge him.

Even when charges were finally brought against teenagers Neil Acourt, then 17, and Luke Knight, then 16, the case was eventually dropped by the Crown Prosecution Service on July 29.

It was left to the Lawrence family to launch their own private prosecution a year after their son's murder, against Jamie Acourt, Neil Acourt, Norris, Luke Knight and Dobson, in April 1994.

Charges against Jamie Acourt and Norris were dropped before the trial and the other three were acquitted after Duwayne Brooks's evidence fell apart under questioning.

Two internal police inquiries followed, clearing the investigation team of any wrongdoing.

But, in 1997, Home secretary Jack Straw announced an inquiry into the police investigation which had failed to bring a single suspect to trial, culminating in the landmark 1999 Macpherson report.

Famously, it concluded "the investigation was marred by a combination of professional incompetence, institutional racism and a failure of leadership by senior officers."

Among the findings were "a marked lack of co-ordination and attention to detail" during the early hours of the investigation.

The inquiry revealed beliefs among senior police that the murder was not racist "when it so clearly was."

And Macpherson heard that the Lawrence family "were not dealt with or treated as they should have been" during the investigation due to "unwitting racism".

Along with this, Michael Mansfield, representing the family, claimed that the conduct of senior officers was tainted by their knowledge of, and possible involvement with, Norris's gangster father Clifford, from Chislehurst.

His allegations were not borne out by the inquiry's findings. But in 2006, BBC documentary 'The Boys Who Killed Stephen Lawrence' made new allegations of police corruption.

It alleged that DS Davidson had taken bribes from Clifford Norris, something the retired policeman denied. An Independent Police Complaint Commission investigation was to find no evidence of a link between the men.

During the 2011 trial itself, it often seemed as though it was the police who were defending themselves, accused of a variety of failures to properly deal with, and protect, forensic evidence taken from Mr Lawrence and the accused men.

In the early 1990s, at a time when there was less awareness of dealing with forensics, exhibits were kept in brown paper envelopes, sealed with Sellotape. Sometimes, exhibits were placed in the same large bag as one another, and as time wore on, warnings that there was a risk of contamination seemed to be ignored.

One policeman, Detective Constable Paul Steed, even deliberately changed seal numbers on some of the evidence bags in what the court heard was a deliberate act of vandalism.

But fortunately, this time, mistakes by police in charge were not enough to save Dobson and Norris from jail.