Does black British 'supergrass' case represent a success?
Four people are facing life sentences after Britain's first black "supergrass" gave evidence against them during a number of trials at the Old Bailey. Does it represent a breakthrough by police?
As he was led away in handcuffs having given evidence at the Old Bailey, Darren Mathurin had the look of someone who knew he would forever be glancing over his shoulder.
Supergrasses - beginning with Bertie Smalls in 1974 - have always negotiated deals while in custody awaiting trial.
What makes Mathurin's case unusual - aside from his ethnicity - is that his deal came after he had been convicted, in December 2008 of murdering Jahmall Moore and been jailed for life with a minimum tariff of 22 years.
He subsequently did a deal with the police and the Crown Prosecution Service and his sentence was reduced to eight years. In return he agreed to give evidence at several trials.
The most recent ended on Monday with three men being sentenced to life for the murder of Leon Labastide in 2004.
Gavin Grant, 26, Gareth Downie, 25, and Damian Williams, 32, were told they must spend at least 25 years in jail.
Suzella Palmer, a criminologist at the University of Bedfordshire, said there was a reticence to help the police in many black communities.
"There is no grassing culture. If you grass, the repercussions are very serious," she said.
Ms Palmer, who was also brought up on the Stonebridge estate, said: "In nine out of 10 cases the community knows who is responsible. Names go around. People know who the culprits are, but whether they share it with the police is unlikely. The police are almost irrelevant."
Gus John, a professor of education who has worked with gangs in Manchester and Birmingham, said: "There has been a wall of silence going up across the country as far this type of crime, and this represents a dent in that wall.
"You can see why the police and the judiciary would decide to make a gesture in reducing his sentence."
In May 2009, 28-year-old Shakah Anderson was acquitted after an Old Bailey jury rejected Mathurin's evidence.
Stephen Batten QC, prosecuting, admitted to the jury Mathurin "had a history of a life of crime" but said the alternative to offering him a deal was "murderers may go free".
Mathurin claimed he was only the getaway driver in the killing of Jahmall Moore in January 2005 - naming Romain Whyte and a second man as the gunmen.
In May 2006 Mr Whyte and the second man were convicted and jailed for life for Moore's murder but their convictions were later overturned on appeal.
The background to the killings starts in January 2004 when the flat of Mr Whyte's girlfriend was burgled while he was in hospital. She suffered broken legs when she jumped out of a window to escape.
Leon Labastide, suspected of involvement in the burglary, was shot dead, sparking a series of tit-for-tat shootings between Mr Whyte's friends and another group, who included Jahmall Moore.
In January 2005 anonymous typewritten letters were sent to Mr Whyte and several other men.
The letters read: "MURDERER 23/05/04 at 22.20
"I know what you did on this date at this time.
"What you do in the dark will come out in the light and everyone will know what it is that you did. If it don't come out the people that matter will still know!!!
"YOU WILL NOT GET AWAY YOUR PAST WILL HAUNT YOU!!!!"
Mr Moore's friend, Sean "Fusey" Cephinis, who was acquitted in 2001 of murdering a man at the Notting Hill Carnival, was allegedly the intended target of the second shooting but he left a house in Harlesden shortly before the gunmen arrived. They shot 24-year-old Mr Moore instead.
Mr Whyte was also acquitted of the attempted murder of Mr Cephinis.
Mr Moore's girlfriend, Sasha Newcastle, gave evidence from behind a screen but she admitted lying in previous trials and said she could remember very little about the shooting or what she had said to police.
Unlike some supergrasses - such as Michelle Hogg, who gave evidence against the Securitas robbers - the shaven-headed Mathurin, wearing a grey prison sweatshirt and biting his lip nervously, was not disguised and was not protected by screens.
But Mathurin will be offered a new identity and relocated to another part of the country when he is released from prison.
It is thought his family have also been rehoused.