This Monday's Channel 4 Dispatches programme unearthed another nasty twist in the police cover-up surrounding the murder of Stephen Lawrence.

Just over 20 years ago, in May 1993, 18-year old school student Stephen Lawrence was stabbed to death by a gang of racist thugs, in Eltham. His murderers were known and there was a witness at the scene. But it took 19 years before a conviction was brought against the perpetrators, in 2012. Even then, only two were sentenced - both for life - while the other three are still loose with no further investigation under way.

If the prosecution took so long, it was only due to the Metropolitan police dragging their feet and their reluctance to charge the perpetrators of this racist murder. Its investigation was such a sham, that when the case was first brought to trial, it collapsed for lack of evidence.

If it hadn't been for the tireless campaign conducted by Stephen Lawrence's mother to get the case re-opened, his murderers would all have got away with it. But by highlighting the fact that the murder of a black youth was obviously not worth bothering about for the Met and by exposing the protection it was effectively providing to racist thugs, Doreen Lawrence forced the Blair government to commission the MacPherson enquiry into the Met, in 1997. Its findings exposed the "institutional racism" permeating the Met and initiated a process which led, eventually, to the re-opening of the Stephen Lawrence case, in 2006.

Police conspiracy

What the Channel 4 investigation has now uncovered, is that in the months following the murder, the Met got one of its special units to seek information to discredit the campaigners, including Stephen Lawrence's family - instead of seeking evidence against the murderers.

Peter Francis, the whistleblower who informed the Channel 4 team, was, at the time, a member of a so-called "Special Demonstration Squad" or SDS - a unit of undercover officers who were paid to infiltrate left political groups and campaigns in order to gather intelligence against them.

Francis testifies that for several years following Stephen Lawrence's murder, he was instructed to pose as an anti-racist activist in order to look for "dirt" to discredit the Lawrence family and other members of the campaign. On the basis of his findings there was even an attempt to bring criminal charges against the only direct witness to the murder - which, fortunately, was thrown out by the court as an abuse of the legal process.

Over all this time, says Francis, the Lawrence family's home was watched and the name of all visitors collected and checked by Special Branch, in an attempt to find some "subversive" connection which could then have been used to undermine the campaign's efforts to get justice.

Of course, this was all in vain. But what if the Lawrences or their friends had been trade-union or left-wing activists? What if Stephen Lawrence had had, among his acquaintances, someone with a criminal record? Would this have been used to smear the Stephen Lawrence campaign, justify the Met's inaction and allow the racist murderers to stay loose? Of course it would have. Because such was precisely the aim of the Met's game.

An instrument against the exploited

Today, of course, now that the Met has different senior officers and that it's been allegedly "cleaned" of its "institutional racism", it's quick to acknowledge the seriousness of Francis' revelations. But so what? It's too easy for claim that Francis' SDS unit has long been disbanded and that these days are over!

But have they? The SDS may have disappeared, but it's been replaced by a "National Public Order Intelligence Unit", with the same brief. In the old days such "undercover police officers" used to be called "agent provocateurs" - and that's what they are: they provoke the repression of protests and opposition groups.

As to the police's "institutional racism" against non-whites - but also, more generally, against poor people - one need only look at the statistics of deaths and cases of ill-treatment in police custody to see that it's still rife.

But how could it be otherwise, when the role of the police is to defend the private property and the absurdly luxurious lives of the tiny capitalist class which owns everything in this society, against the demands and needs of the working class majority? That the bodyguards of the capitalist fat cats, who live on our backs, should behave like thugs, only reflects the thuggish nature of capitalist profiteering in the first place. And changing this will require the overthrow of this entire, rotten, system!