Convicted: The duo 'infected with gross, revolting racism'

Norris shouted 'nigger' at black police officer one mile from spot where Lawrence was killed - then Acourt drove car at him

The five suspects for the murder of Stephen Lawrence were described by the inquiry report into the botched police investigation as "infected and invaded by gross and revolting racism".

For nearly a decade the Metropolitan Police have been trying to put the five men behind bars for the stabbing of the black 18-year-old at a bus stop in Eltham, south-east London, in April 1993.

Yesterday, two of the suspects were locked up and now face a substantial stretch in jail after the police secured a conviction for an offence unrelated to Stephen's murder.

David Norris, 25, and Neil Acourt, 27, could be imprisoned for up to two years after a jury found them guilty of carrying out a racist attack on an off-duty black police officer.

In May last year, Norris, a passenger in a car driven by Acourt threw a drink at Det Con Gareth Reid and shouted "nigger" as the policeman walked home from Eltham railway station – about a mile from where Stephen was murdered.

Acourt drove the car at Det Con Reid as part of a "joint enterprise" with Norris to cause him harassment, alarm or distress motivated "by virtue of one reason and one reason alone – his colour", the court decided. The type of racism exhibited by the two men was precisely the kind of abuse highlighted in the Lawrence inquiry report in 1999 by Sir William Macpherson of Cluny who stressed that Acourt and Norris had been "prime" murder suspects from the very start.

The report published details of secret police surveillance of four of the suspects taken in 1994, a year after Stephen's murder. The surveillance "showed violent racism at its worst," concluded Sir William.

A video of the men mouthing racist obscenities and wielding knives included Neil Acourt saying: "I reckon that every nigger should be chopped up, mate, and they should be left with nothing but f*****g stumps..."

David Norris added: "If I was going to kill myself do you know what I'd do? I'd go and kill every black c**t, every Paki, every copper, every mug that I know."

After Stephen's murder, attempts to prosecute Norris, Acourt and his brother Jamie, Gary Dobson and Luke Knight all ended in failure.

Since the collapse of the case and the criticism meted out to Scotland Yard, which was accused of "institutionalised racism" by the Macpherson report, the police have spent an estimated £30m in the past three years re-investigating the murder.

The inquiry had included keeping all five suspects, their families and friends, under close scrutiny. New evidence is being examined by the Crown Prosecution Service, but it is expected to conclude that there is insufficient evidence to bring fresh charges.

During the trial that ended yesterday, Norris, the son of south London gangster Clifford Norris, who has recently been released from a nine-and-a-half year prison sentence for conspiracy to import drugs and possessing a loaded firearm, spoke of the stress he had experienced of being under investigation for nearly a decade.

He told the jury at Woolwich Crown Court: "Basically, I have had nearly 10 years of constant pressure. Not just me, my family, my children and my mother and father. I have four children – one of them is disabled and I have had enough.

"I have had people threatening to kill us by sending letters to the home. It has been a nightmare for nearly 10 years."

Acourt claimed the case was a "fit up" by the police.

Certainly, during the past decade Norris and Neil Acourt have had plenty of contact with the authorities. In May 1999 the two men were fined for stealing empty soda siphons worth £224 during a break-in at a drinks warehouse.

In February 2001, Acourt was given 50 hours' community service and ordered to pay £100 costs for keeping an extendable metal baton in his car. Acourt, who said that he had also changed his surname to his mother's maiden name, Stuart, claimed he needed the offensive weapon because he feared revenge attacks.

He was cleared in the same month of trafficking illegal immigrants into the UK in a trial in which one of his close friends was jailed. The case was dropped against him after there was found to be insufficient evidence to prove his involvement. John Caetano, 27, and Acourt had been charged jointly with concealing seven people from India and Ecuador in a van bound for Dover.

Norris was jailed for three months in July 1999 after he admitted driving while disqualified and a series of motoring offences.

Norris, who has previous convictions for driving while disqualified and theft, was also fined a total of £150 for having a defective tyre and driving a car in a dangerous condition. He had his licence endorsed for having no insurance.

After the verdict yesterday Sgt Ravi Chand, president of the national Black Police Association, said: "I am delighted that at last individuals who have behaved in such a despicable way have been brought to justice ... I hope it sends out a clear message to others who perpetrate such acts that the full force of the law will used to deal with their behaviour.

Scotland Yard will no doubt be pleased at the imprisonment of two of the men. But they will inevitably consider it poor consolation for their real goal, that of convicting Stephen Lawrence's killers.