Andrew Anthony on the stabbing to death of London teenager Kodjo Yenga

In March 2007, Kodjo Yenga, a refugee from Congo and a popular A-level student, was stabbed to death in Hammersmith – just one of the 54 young men who have died on London's streets in the past two years. Here, Andrew Anthony goes in search of some answers to a tragic and motiveless crime

The laptop on Detective Inspector Tim Wilkinson's desk displays a frozen image of a well-built teenager and his girlfriend. It is a CCTV frame taken from a security camera in the Hammersmith Broadway shopping centre around 4.30pm on Wednesday 14 March 2007. The boy is Kodjo Yenga, a 16-year-old A-level student from Ladbroke Grove in west London, with ambitions to become a graphic designer and, perhaps, a musical entrepreneur. He wears a large belt and buckle around his jeans, but otherwise there is nothing that would make him stand out in a crowd. Or at least there is no clue that he has less than half an hour to live.

I visited Wilkinson in September at Hertford House, a redbrick building at the end of a long cul-de-sac, next to the Barking exit of the North Circular. Set amid the nondescript sprawl of offices and industrial estates that line the border of London and Essex, it looks like it might be the headquarters of a small insurance firm. In fact, it's one of the main bases for the capital's dedicated Homicide and Serious Crime Command.

A firm-set man with a bald crop and a dry delivery, the homicide detective could be the comedian Jack Dee's stockier and more serious brother. In an email, he had described the case I wanted to discuss with him as 'professionally satisfying, but personally disturbing... given the ages of those involved'. Pressing 'Play' on the computer, Wilkinson talked me through the 30 minutes of footage assembled from over 100 hours of film from CCTV cameras in and around the Hammersmith area. It begins with Kodjo and his girlfriend, who is known as Cookie, getting into a lift at the shopping arcade with a puppy. Apparently a security guard had told the couple that they had to leave the arcade because the dog was barking. As they emerge from the lift, they run into a group of five teenage boys, some of them wearing school uniform. Cookie speaks to a couple of the group, whom she knows from the nearby Shepherd's Bush area. They chat for a while and then one of the boys, Tirrell Davis, says something to Kodjo. Later, in court, it is said that his actual words were: 'I hear you want to fight me.' Kodjo initially declines the offer. 'No,' he is supposed to have said, 'I don't want to fight with you because you're a little boy.'

Tirrell, who was three weeks away from his 16th birthday at the time, is persistent, and a discussion takes place. There are a few minutes of the boys shifting back and forth, before eventually Kodjo agrees to Tirrell's challenge.

Aside from Cookie, there are also three girls attached to the extended group - friends or girlfriends of the boys. A succession of security cameras captures the group's slow, stretched-out progress from the shopping centre to Hammersmith Grove, a handsome residential avenue of large Victorian houses.

With up to 4.2m CCTV cameras, Britain is one of the most monitored nations in the world, and in recent years there has been a protracted debate about the 'surveillance society'. Wilkinson was sympathetic to the concern, but he hastened to point out that nearly all the cameras record images that will never be seen by a human eye. 'There isn't anyone watching, and they're regularly wiped clean,' he said. The exception being when something goes wrong. In such circumstances, if the police act with sufficient speed, they can grab footage and examine the minutiae of apparently unremarkable events that not even the most attentive witness could hope to recall.

As the group of 10 teenagers heads north from the large roundabout of Hammersmith Broadway, it splits into discrete but changing sections. For a while Kodjo and Cookie are separate from the others, then Cookie briefly joins a couple of the girls. There is even a moment when Kodjo and Tirrell walk alongside each other and exchange a few words. A passer-by could have thought they were two friends. But there is a narrative taking place whose meaning would have been lost on the casual observer. Tirrell makes some phone calls, as does Kodjo, with differing, not to say fatal, results. 'Notice that,' says Wilkinson, pointing to something I'd missed. A small backpack passes hands between Tirrell and another boy, Brandon Richmond. This exchange, invisible to the disinterested observer, will later take on decisive significance.

Two trendy young white men come into the frame of the footage and hug - a gesture of genteel bonhomie that seems suddenly incongruous against the violence that is about to unfold, as if the chattering class had unknowingly trespassed on another, harsher world - and then disappear. The teenagers come to a stop outside The Grove - a stylish gastropub at the junction of Hammersmith Grove and Adie Road, and are recorded on its external security cameras. Kodjo stands apart, leaning against a bollard, facing towards Adie Road. He looks anxious, as if he's not sure about his surroundings, but he doesn't leave. He doesn't walk away.

Tirrell pulls up a chair from the bar's terrace and begins to goad Kodjo. Brandon sits down as well. They both address Kodjo, who doesn't respond. He's waiting for backup. It's known that he phoned several friends, but the two he most wanted to join him were playing football.

Kodjo had good reason to call for support. His friend, Seun Adeboyoje, had suffered a campaign of intimidation in the previous weeks. Seun had received threatening phone calls from a number of boys, including Tirrell. His sister had been attacked in school by a boy with a knife and CS gas, and one of his friends was struck with bricks. On 17 February, Seun was challenged to a 'one on one' fight, only to be set upon by a group made up of three of the same youths who now confront Kodjo. They chased Seun through Shepherd's Bush market and cornered him in a textile shop, where they repeatedly punched, kicked and stamped on him. Then one boy emptied boiling water from a kettle over Seun's face and arm, while another continued to stamp on his head.

The two friends who do eventually show up outside The Grove look nervous and unsuited to the situation. They are not street-fighters, and even if they were, there is probably little they could do. From Adie Road, eight or nine boys arrive with a bull terrier that runs at Kodjo.

Off camera, there are a series of brief clashes, during which the gang produces several knives and a baseball bat. 'Do you think you are a big boy because you have a knife to me?' Kodjo is known to have said, when confronted with one of the weapons. 'I don't care,' was the reply of the boy holding the knife.

'I want you to respect me.'

Respect is one of those words whose core meaning has been perversely transformed in modern urban usage. Instead of signifying appreciation or admiration, it has become a synonym for 'fear'. Thus to not fear someone is to disrespect them. This appears to have been what provoked the rage of Kodjo's attackers: that he was not scared. And one of the more distressing aspects of the case, in terms of the healthy development of young men, is that if he had been more scared, he might well be alive today.

The last shot the film records is of Kodjo backing away as the dog, followed by Tirrell, Brandon, another boy, Michel Williams, and then the rest of the gang move in on him.

Kodjo Yenga was born in 1990 in the Democratic Republic of Congo
, or Zaire, as it was then called. His father was Alfred Liyolo, a renowned sculptor, and his mother Ladjua Lesele, a civil servant who worked for the department of education. They lived a comfortable life in Kinshasa, the capital, part of an urban elite that managed to thrive in the kleptocracy presided over by the tyrant Mobutu Sese Seko.

'Life was very good,' Ladjua told me in the small flat where she moved after her son's death, 'but I left because I had a political problem at the university. We had a lot of trouble. Family members were killed, there was no safety. I was worried for Kodjo.'

She describes Mobutu's final years as an anarchic power struggle, and when the police looted her house, she decided to flee. This was in 1994, three years before Mobutu was finally ousted. Leaving Liyolo behind in Kinshasa, where he remains a successful artist today, she and Kodjo flew to London.

Ladjua is a big woman with the kind of noble features that a sculptor might appreciate. Her face is transformed, on occasion, by a broad smile, but her eyes betray an undiminishing internal pain. 'For me,' she said, 'I have no life anymore.' Though she has lived in England for almost 14 years, she speaks very limited English. Part of the reason for this, she says, is that Kodjo acted as her translator for the outside world. 'I taught my son to speak and write French,' she explained. 'That's why I have the problem to talk.'

When they first arrived, they lived in South Kensington, where French speakers were commonplace. Kodjo attended Marlborough Primary School in Sloane Avenue. 'He made friends very quickly,' his mother recalled. 'He was popular and a good worker. For him, the first thing was the school. Life was normal for him. It was only me, I knew the reality, and I tried to protect him from the trauma.'

The family then moved to Ladbroke Grove and Kodjo went to Henry Compton secondary school in Fulham. It is Linford Christie's old school, an inner London comprehensive that takes more than its fair share of unruly children. But by all accounts, Kodjo never got into trouble.

'He'd have the occasional argument,' his old schoolmate Bilal Awonote told me. 'But never fights. All the teachers liked him. He wasn't like the rest of us, he was hardly ever cheeky.'

Paul O'Shea, the principal at St Charles Catholic Sixth Form College, where Kodjo went on to study for A-levels, confirmed that there were no discipline problems at all with the student. 'The odd deadline missed,' he said, 'but that's all. All his teachers liked him. He was a big personality. He was a 3B boy, perhaps an A in French. He would have got grades a middle-class white family would have been perfectly pleased with.'

O'Shea was insistent that the issue of ethnicity has no helpful place in the discussion of the teenage gang violence that has plagued the capital in the past couple of years. He noted, as many others have done, that Glasgow has long been bedevilled by gang and knife crime, nearly all of it 'white'. Nonetheless, the comparison to the 'white middle class' illustrates how perceptions of race unavoidably intrude on this story.

St Charles has a BME (black and minority ethnic) profile of around 80 per cent. In the past two years it has held memorial services for two murdered students - Kodjo, and Nassirudeen Osawe, who was stabbed to death in Islington last December, following a row at a bus stop. The school has an enviable academic record, a policy of strict discipline, a highly motivated staff and a successful body of students, of which both Kodjo and 'Naz' appeared to play an active part. Many of the students perform charitable works, here and abroad, and there is a commitment to help local old people. This is where the Glasgow analogy becomes less appropriate. In the normal course of events, even in Glasgow, such a school would not expect to produce two murder victims inside nine months.

For O'Shea, a slightly built man with the creased expression of a stoical optimist, the key issues surrounding the deaths of Kodjo and Naz are a crisis of masculinity and social demoralisation. After the murders, he asked Shaun Bailey, a local youth worker and prospective Conservative parliamentary candidate for Hammersmith and Shepherd's Bush, to come and speak to the school. Bailey, a black man who grew up in a single-parent family in the area, preaches against the adoption of a victim mentality, appealing to black youths to take responsibility for their actions. In a pamphlet he wrote, entitled No Man's Land, he described the attraction of gangs to young boys: 'They seem to be tough. They seem to be having a good time. Nobody interferes with them. And when you are a boy, with that whole wanting to be a man, these appear to be men to you. If anybody messes them, they can fix it.'

'I suppose bringing Shaun in was implicitly addressing the fact that this isn't how the black community wants to be perceived,' O'Shea conceded, 'and the black community needs to respond honestly and positively to the challenge.' Then he added: 'I remember he said that what will determine your life chances is who you "move" with.'

Bilal Awonote had always moved with Kodjo. They'd been best friends since nursery school, and, after the murder, Bilal left home and stayed with Ladjua for seven months. Recently, he had a portrait of his late friend tattooed on his arm. A bright young man, unafraid to voice his opinion, Bilal possesses an unusually charismatic sparkle. By turns entertaining, perceptive and brooding, he thought of himself and Kodjo as complementary opposites. 'He was a laid-back, cool character, like the guy in Grease in the black leather jacket,' he said. 'He made sure he never picked sides in disputes. If you argued with him, he'd let you win. He'd say, "Yeah, whatever. When you want to talk to me, let me know."'

Ladjua's house became a focal point for Kodjo's friends. Everyone would hang out there at weekends, and Ladjua would often cook a meal for them all. The boys knew how to pose, adopt the look of imposing young men, but to them it was little more than a fashion statement. One day Bilal and Kodjo decided to give themselves and their friends a group name: Ride For Life, or RFL. 'We were just a small collective into music. Just that, nothing else,' Bilal explained, defensively. 'And if a group of white middle-class kids did the same, no one would think about it.'

According to Bilal and several other friends, the group had a philosophy of sorts. It was against street violence and in favour of academic and professional success. The way Bilal tells it, RFL became a kind social and conceptual refuge from the street. 'Everyone who was in RFL got into college, was working, or is going to university in September,' said Bilal proudly. Some kids joined who had previously been in trouble or carried knives, he said, but RFL showed them a different way. 'What kind of gangsta goes to school every day and gets As?' he asked.

They were, in a sense, the anti-gang, in favour of social conformity, hard work and individual responsibility. Bilal, for instance, was damning of teen mothers and the boyfriends who impregnate them. 'I've noticed that a lot of girls, especially in our environment, working-class black, are attracted to negativity,' he said. 'You get pregnant for the boy that's going to prison. If a guy goes to prison, he's seen as tough and strong. The qualities that people admire are the qualities that won't get a person anywhere in life. It's really sad but that's the way it is.'

The RFL crowd spent a lot of time at a place near Ladbroke Grove called YCTV (Youth Culture Television), a cross between a youth club and a production training scheme. Set up as a charity by Sabrina Guinness, its basic aim is to familiarise street kids with media skills. It also helps to keep those kids off the streets. One of the project managers at YCTV was Andy Gray, a wiry, ebullient man in his thirties who had been in trouble in his youth. He rolled up his shirt at one stage to show me a long and livid scar, courtesy of a knife fight. On that occasion, he said, he came within inches of death. In his case, the catalyst for changing his ways was having children: 'I wanted better for them, and myself.'

Kodjo, he told me, was definitely not the kind of boy he had been. 'I've taught over 1,000 kids,' he said, 'and, I mean this, he was the most polite and respectful I've dealt with.'

Gray told me that he liked to josh around with the kids, pull their legs and so forth. Most of them would react, sometimes with a derogatory response. But never Kodjo. 'He'd just smile and say: "You're trying it."'

YCTV had a zero-tolerance policy on offensive lyrics, so there was no intimidating language. 'No foolishness,' as Gray puts it. 'No nonsense.'

Gray showed me film he'd shot of Kodjo performing. In front of the camera, and an audience of his peers, Kodjo raps a love song he wrote. The song is about his 'chocolate-chip Cookie'. He sings: 'It's like we're so close I can feel you flow through my veins, trying to get to my heart. The last girl that got there, she had to rip it apart.'

I told Gray that I thought Kodjo looked shy, but not at all embarrassed, and sang the words as if he meant them. 'Yeah,' Gray said, 'he's confident about being a man.'

By all accounts, Kodjo was something of a chivalrous romantic. He first met Cookie when he rescued her after her heel got stuck in a pavement on Goldhawk Road. They went out together - or 'linked' - for two years. With the money he earned from weekend and holiday jobs he bought her a dress, a puppy and a gold chain with a 'K' - his nickname was Kizzle.

'I just thought he was cool,' remembered Cookie, now a confident and effervescent 16-year-old. 'He was smart and funny and he was romantic. He used to tutor me in maths. He was really good at maths. I got a B in my GCSE.'

Cookie has her own tattoo commemorating Kodjo. It says 'I love you'. She is working at the moment on a school project on knife crime. 'I was 14 and I watched my boyfriend die,' she said. 'A lot of people say, "You're impressive, you look like nothing's happened to you." But I'm really trying to get the message across that it's painful. I lost my boyfriend, but, even worse, I knew who they [the killers] were. So it was a double barrel of hurt. You're looking at consequences. You're looking at crying mothers, and funerals and you're also looking at me. I'm not saying I'm that important, but the girlfriends do go through so much.'

At first Ladjua wasn't keen on her son having a girlfriend. She wanted him to focus on schoolwork and leave girls until later. Eventually, she accepted the relationship. Her real concern, anyway, was not so much girls, as other boys and violence. 'I talked to Kodjo every day,' she said. 'I would ask him which place he'd go. I'd know exactly where he was. I'd call him on the mobile phone and when he came home, he told me everything he did. He would leave me letters telling me what he was doing. He'd say, "Don't worry, Mama, I take care of myself."'

Ladjua imposed a nine o'clock curfew on her son, a restriction unique among his friends. He seldom went out during the week, and on Sunday he would spend the day with his mother, at church and in the house. Ali El-Baarini, another of Kodjo's friends, told me: 'We used to call him up and he'd say, "I'm doing washing for Mum all day." He used to go from school to home and work five hours, and then one day he's dead. So what's the point? He could have just gone out and had fun.'

On the day that he was killed, Kodjo was on an errand to buy a white toilet seat for his mother. He met his friend Seun, who, a month before, had been assaulted. At some point an argument developed between Seun and a girl who, he says, was a friend of the boys who had attacked him. Seun maintains that, without provocation, she came up to him and said, 'What are you looking at? Do you want to get burned again?' In any case, a shouting match developed, the police arrived and Seun was arrested. DI Wilkinson believes that it could well have saved Seun's life.

Afterwards, Kodjo went out to lunch with Cookie and her mother. They handed Cookie's puppy to another friend, Cherelle Mitchell. She looked after the dog for about an hour, but then noticed a boy 'just watching me' so she called Kodjo to come and collect the dog. And that's when he was asked to leave by the security guard.

'He starts saying take care of myself,' Cherelle recalled. 'He didn't have no expression on his face.'

Did he think he was about to face danger?

'I don't know,' Cherelle said. 'But the way he was talking, it didn't seem right. He was a bit worried.'

In one sense, these were all typical teenage interactions, but in view of what then took place they pose a question. Did Seun or Kodjo expect to encounter trouble? The ground floor of Hammersmith Broadway is a well-known meeting place for teenagers, and not infrequently the scene of arguments or fights that the police are called upon to break up.

In court, it was said that a girl came up to Tirrell in Hammersmith Broadway and said, pointing out Kodjo, 'That's the boy who called you a pussy.' To which Tirrell replied: 'Yeah, I know, that's why I'm down here.'

Both Cookie and Seun insist that there was no pre-arrangement. All Kodjo's friends are adamant that he avoided fighting.

Seun also told me repeatedly that there was no motivation he knew of for the original intimidation and the assault with the boiling water. 'Basically,' he says, 'I think that they attacked us because we lived in the area, and they wanted to gain status.'

In May this year, five boys were convicted at the Old Bailey of crimes relating to Kodjo Yenga's murder. Brandon Richmond, who was 13 at the time of the crime, and Tirrell Davis, who was 15, were found guilty of murder. They were jailed for life and ordered to serve a minimum of 15 years. Three others were found guilty of manslaughter, and were sentenced to 10 years, with five years licence on release : Kurtis Yehmoh, then 16, who was released on bail on the morning of the attack (in a separate case involving the intimidation of a witness), Michel Williams, who was 13, and Jamal Bridgeman, then 14.

It was one of a spate of teenage murders in the capital that left both the authorities and the public recoiling in impotent horror. Twenty-seven teenagers were murdered in London in 2007 (18 stabbed, eight shot, and one beaten to death). It was the worst year on record for fatal teenage violence - until 2008. The 27th teenage victim this year was killed in September. Since then there has been something of a Metropolitan police 'surge' against knife crime. Between 14 May and 28 July this year 49,000 stop and searches were conducted, 2,000 arrests made and 1,445 knives recovered. It seems to have stopped or slowed the killing, but few in the police believe it is anything other than a temporary answer to a long-term trend.

'Any solutions have to extend beyond the life of a headline or the term of parliament,' cautioned DI Wilkinson. 'Teenage boys have always fought; the difference is now a small minority are doing so with knives.' But why? Is it just adolescent delinquency in a new, more aggressive form, or are the teenage murders a symptom of much wider social malaise? If so, is the rise of teenage gangs a lethal manifestation of a communal failing?

In court, Kodjo's killers were said to be members or associates of a gang called the MDP, which according to newspaper reports stood for either Murder Dem Pussies or Money Drugs Power. A number of his friends told me that Kodjo was liked by the main body of the MDP. According to Seun, he and Kodjo had been asked to join the MDP, but turned the offer down because 'we didn't want to be involved in any of that'. Many street gangs contain hierarchies of age, with 'youngers' or 'tinies' occupying the lowest rung. There is talk of initiation rites, committing crimes to show allegiance. It's been suggested that Kodjo's murder was itself a form of initiation. Most young people I spoke to dismissed the theory of an organised 'hit'. Instead, they thought the 'youngers' were independently trying to make a name for themselves.

Until a few weeks ago, when they were removed by the server, YouTube featured a number of videos under the heading of 'MDP'. All of them showed scenes of around 10-20 hooded boys standing huddled together in the hallway of a council estate. Some of the youths have their faces covered with bandanas or scarves, and all of them stare menacingly into the video camera - as if it were a potential victim - as they take turns rapping. The lyrics are violent and threatening, detailing the injuries that would befall anyone who makes the error of crossing or disrespecting the singer and his cohorts.

This kind of aggravated bravado is inherent to the genre of gangsta rap, and one reading of these videos is that the participants are simply imitating the style of well-known artists. But did some boys go further than invoke the postures of rap, and adopt the gangsta ethic itself?

A local Labour councillor named Marianne Alapini, who was a spokeswoman for Kodjo's mother during the trial, told me that she had heard of a case of a 13-year-old girl suffering a multiple rape, and a branding, at the hands of MDP members (the police have no record of a crime fitting this description).

At the time of Kodjo's death the police officer in charge of community aspects of local policing in Shepherd's Bush and Hammersmith was Chief Inspector, now Superintendent, John Sutherland. A devout Christian, Sutherland is an impassioned advocate for young people. Fresh-faced and in his 30s, he looks almost youthful enough to quality for the demographic himself. He is keen to emphasise that the overwhelming majority of teenagers are well behaved and productive. Nonetheless, he accepts that, against a backdrop of falling violent crime, the degree of teenage violence appears to have increased in London. There is little doubt that serious crime offenders are getting younger. Among a small, but growing, number of urban youth, Sutherland contended, there is a chronic lack of understanding of cause and effect, and in particular the personal and social consequences of violent actions.

'Are the MDP a gang?' Sutherland asked rhetorically in his new office in Islington. 'Of course they're a gang. But are they the same kind of gang as those operating in south London, involved in organised crime at a relatively high level? Well, no, they're a completely different beast.' The academic David Kennedy, architect of the anti-gang strategy that led to the so-called Boston Ceasefire, recently held a briefing at Scotland Yard in which he suggested that a lot of time and effort was wasted in attempting to define the term 'gang'. Sutherland agrees.

He described a sliding scale that goes from organised crime at the top to organised criminality in the middle, to 'friendship groups that have nothing to do with crime whatsoever', like RFL, at the bottom.

'They had just given themselves a name, but for no criminal intent at all, so far as I know and am aware,' he said.

The MDP, according to Sutherland, were somewhere in the middle to lower end of the scale, involved in the commission of street robberies. He acknowledged, however, that there was an established, though far from inevitable, path of criminal progression. 'My concern,' he said, 'is that the escalation of offending is accelerating. In a minority of cases, some individuals go from 0-60 much faster than ever before. Some of those involved in the murders of the past 18 months have almost no criminal antecedents at all.

It's not predictable, and the randomness is concerning.'

Sutherland thinks the speed of technology is one of the reasons the steps to extreme violence have accelerated: 'Something that a few years ago would have taken a week to do the rounds, can literally happen within 60 seconds.'

So it was that a flurry of phone calls and text messages brought several of Kodjo's attackers to Hammersmith to witness - or partake in - the fight. The superintendent also outlined factors that research had shown were often common to those who became involved in violence: broken homes, absent fathers, absence of positive role models, and some experience of abuse or violence, either as a victim or witness. Sutherland was reluctant to hypothesise, beyond factors such as poverty and social disadvantage, on why so many of the victims and perpetrators in the London teenage murders were from an Afro-Caribbean and African background. He was also cautious about ascribing the violence to the malign effect of specific cultural figureheads.

'I don't think 50 Cent is to blame for any of the murders in London,' he said. 'But I do think there are a number of factors that are about culture and technology colliding that are desperately unhelpful. If you take the violence that is apparent in some rap music, if you combine that with violence apparent in an awful lot of video games, feature films and horror porn, combine that with material available on the internet - and I would include pornography along with the violent stuff, because it does a lot to reinforce misogyny and it's not unusual for gangs that are involved in violent street crime to also crop up in a gang rape scenario. If you take any of those, either in isolation or together: do I think they are to blame? No. Do I think they help or hinder? I think they profoundly hinder.'

I met the mother of one of the boys convicted of Kodjo's murder at a coffee bar in Shepherd's Bush. She asked me not to mention her name, so I'll call her Gloria, and her son Boy C. Gloria is in her mid-thirties, a tall woman with a stylish braid of dreadlocks and a sizable personality. She is, she told me, a born-again Christian.

When Gloria was 18 her mother and sister died on holiday in a hotel accident in Sierre Leone. She wasn't close to her father and she felt suddenly alone. 'I was always looking for somebody,' she said, 'and unfortunately the person I met was Winston.'

By the time she was 20, she had given birth to Boy C. Winston disappeared when she was 14 weeks pregnant, not returning, she said, until his son was five weeks old. She found the boy a challenge from an early age. 'I'd never even babysat for anyone, so it was a big shock to the system when I had my own baby.'

Winston was seldom around, and when he was, Gloria couldn't count on him. One time, when Boy C was two years old, Gloria went to stay with a friend in Brighton and left the boy with his father. A couple of days into her break, she got a call informing her that her son was in foster care. Apparently Winston had not picked the boy up from nursery, and when he was contacted, he said he had to work. Gloria was warned that if it happened again the boy would be taken from her by social services.

After that, the father withdrew from the boy's life until he was five or six, at which point he said he wanted to try again. The couple got back together, but it didn't work and once more Winston disappeared. Gloria met another man, who found it hard to develop a fatherly relationship with Boy C. He couldn't understand his behavioural problems because, said Gloria, the stepfather, like Winston, was 'from the West Indies and I think they're a lot more disciplined over there'.

Boy C would disrupt the class in his primary school, which Gloria thought was too lax an environment for her son. When he was nine, the family went to stay with the stepfather's parents in Trinidad. While there, Gloria decided to leave the boy with her in-laws.

'I thought, let's give him a go here, because obviously they've got more discipline over there, and I enrolled him at school. He thought I was joking,' recalled Gloria. 'Even up at the airport, he thought, "Nah, Mum's not leaving me here." But I thought, you know what, we've got to try something because this boy is getting really challenging. So we left him.'

How did the boy respond, I wondered?

'He was very quiet. I don't think he could believe it until he saw us going through the exit tunnel,' said Gloria.

This seems like a particularly callous action, but it's obvious that Gloria is not a callous woman. She speaks of her son with real affection, and argues that his behaviour and school work made a dramatic improvement in Trinidad. She visited him a couple of times, and he came to London. Then in January 2004 she gave birth to her daughter. At that point, she thought it was unfair to keep her son in Trinidad while having a new family, so in July he returned home and began secondary school.

Very soon, his behaviour began to deteriorate. He would get into a fight or disrupt the class. He didn't really have any friends.

'I used to try everything,' said Gloria, shaking her head. 'He never even used to know why he got into trouble. He'd just say school was boring. I regret putting him in a boys' school. There was too much testosterone flying around.'

He started going to the local youth club in Shepherd's Bush, where he rekindled friendships he'd had before he went to Trinidad. Among this new social group was one of the boys with whom he'd later stand trial. Around this time, in 2006, he also gained a social worker I'll call Simon. 'When I saw him,' said Gloria, 'I thought "What can you do? You won't understand, a white man from New Zealand." But that man was a godsend.'

When I met Simon, he described Boy C as one of the least difficult boys he had to deal with. He was not someone, he believes, who was an instigator by nature, but rather easily led. In his time with Boy C, Simon offered strategies to cope with familial disagreements and school disputes, and for a while they delivered results on both fronts.

However, after a period, his behaviour declined once more. He grew taller and more developed, rivalling his mother's physical stature. At the same time, Gloria was pregnant with her third child. She wanted to go away for Christmas to Trinidad, but the school said that if she took Boy C out for such an extended period, he would be expelled. So she arranged for her son to stay with her cousin, and went to Trinidad with her husband and daughter.

Meanwhile, Simon returned to New Zealand for the Christmas break. A series of arguments broke out between Gloria's cousin and Boy C. He was staying out late, not listening to her, and eventually she snapped and smacked him. In January, back in London, Gloria learned that customs had refused Simon re-entry to the country, owing to an out-of-date visa. 'That was the last thing I wanted to hear,' she said. In his place, they got a female student. 'She couldn't do anything,' said Gloria. 'We needed a male.'

From this point, there was a rapid escalation in misbehaviour. Boy C was caught by the police on a stolen moped, then a week later he was arrested for trying to steal a bike and assaulting another boy. Gloria decided to leave her son in the cells for the night. Some months earlier, she had arranged with a community police officer assigned to her son's school for Boy C to visit a police cell, in an effort to discourage behaviour that might lead him there.

'He went in the cell. The door was shut. He saw it wasn't nice. Saw that there was a camera. No privacy. Excrement on the walls. He didn't like it, but obviously a couple of days later, that had gone out of his head.'

After the assault, Gloria tried to get her son into an educational home in Wembley designed to cope with difficult children. The course was prohibitively expensive and she was told by her local council that Boy C was not problematic enough to qualify for that kind of funding (no authority could afford to finance high-intensity care and education for every child who was arrested for fighting).

Gloria had also recruited her pastor to help her with Boy C. When her son was excluded from school, she got him up at 5am to attend morning prayers in Hayes, on the outskirts of London, where her pastor was based. 'I tried everything with him. I tried the Boys to Men scheme in Peckham. I got him into the Boys Brigade. But he never wanted to stick at anything long. He never had interests.'

Then, on 14 March, Gloria came out of church to find her phone full of text messages. She called her husband and learned that Boy C had been arrested on suspicion of murder. Once more in the police cells, the boy appeared calm when his mother arrived. He was dressed in police-issued white overalls and he had brown paper bags around his hands. Gloria was given some time alone with her son and she asked him if he'd done it. He said that he'd just been there to watch a fight.

The next day flashed by in a blur for Gloria. 'I was supposed to go to court,' she said, 'but I never made it. I think I was in a bit of shock.' On Friday the interviewing began and Boy C's solicitor advised him to give a 'No Comment' response to all police questions. Gloria was frustrated by this approach - 'I thought he should tell the truth.' But the solicitor argued that in such a serious case it was the appropriate response.

Her son didn't give evidence at his trial.

'I wanted him to testify,' Gloria told me, 'but they said he'd put himself in real trouble.' Only one boy spoke, and he attributed the murder to a mysterious youth not seen by anyone else. Of the five boys who were found guilty, according to Gloria, only one boy's father attended court every day. Another, who did nightwork, came along when he could. The other fathers, including Boy C's, did not show up.

During the trial, Gloria approached Ladjua and offered her apologies. 'She was so gracious and humble,' Gloria recalled. 'I have the utmost respect for her. It will never be over for her. Thank God I don't have to visit my son in the cemetery.'

Gloria's son is in a youth offenders' institute in Ipswich. She sees him once a month. 'Now he realises everything I was saying,' she said. 'If there's one thing this experience has taught him it's what family is. Before, he never valued us. I was just Mum moaning. Now he realises what Mum is.'

He will not be eligible for release until he is 19, which means that he will have spent almost the whole of his teenhood in custody. 'If that isn't going to make you appreciate your freedom,' Gloria concluded, 'then nothing will.'

When I left Gloria, I walked across Shepherd's Bush Green, a large triangle of grass surrounded by a permanent traffic jam, a parade of shabby shops, a mall and a music venue. It's not the most pleasant spot in London, but then neither is it particularly mean or dangerous. At least to my eyes.

A few days later I got a different perspective when speaking to Simon, Boy C's social worker. 'When I walk across Shepherd's Bush Green,' he said, 'I don't notice anyone and they don't notice me. When [Boy C] walked across Shepherd's Bush Green, he was shitting himself the whole time. Because those two boys over there are from a different postcode. Those boys over there are bigger than him and are going to jack him for his phone. He needs to know what buses he can take, what buses he can't, what time he can be at the station, what time he can't. Contrast that to an environment in which you feel reasonably safe in your neighbourhood, with lots of safe space and time to reflect and relax. That's what you need to emotionally develop. That's what these kids in London are not getting. That's why they get themselves into gangs. And I don't think the general public realise how frightening it is to be a 13-year-old black male in London.'

He described a Hobbesian world of attack or be attacked, yet his analysis was not the kind of liberal apologetics routinely attributed to his profession. He argued that many of the young boys he encounters need discipline and established limits, both on a familial and communal level. 'Adults need to take control back of the world,' he said. 'Teachers should be given the power to restrain children. When kids talk back to the bus driver, it's the duty of every adult to say, "No, you don't talk like that. Show some respect."'

As a foreigner, Simon was surprised how many ethnic groups failed to organise support systems for youngsters from their communities. 'There are strong ethnic community identities here, but not that much community activism. In Shepherd's Bush there is no group of Jamaican men running a project, saying, "These kids are from our culture, we're taking responsibility for them." There's a lack of intracultural ownership. It's a shame, because there are enough individuals around who are good enough role models. You don't actually need a father to be in the home. What you need is adult role models.'

Tellingly, perhaps, it is women who are trying to develop the sort of community initiatives that Simon described. Ladjua has set up the Kodjo Yenga Foundation and Educational Trust to finance underprivileged students through further education. 'I need to give my son as an example to other boys,' she told me. 'Because he was a good boy.' And her spokeswoman, Cllr Alapini, is behind a project called Angels, Divas and Knights, a joint venture with Kensington and Chelsea local authority, which aims to put together 'a comprehensive package of early and positive interventions and intense preventative measures for children and young people who may be vulnerable and at risk of becoming involved in crime'.

Much of what Simon had to say was also echoed at a public meeting I attended at Kodjo's former school, St Charles Sixth Form College. Held by a group called West London Citizens, it brought together students of the school and a variety of local associations, most of them religious, to discuss the problem of 'crime and the fear of crime'. The message from the speakers, who included Paul O'Shea, was strongly Christian, not just in its social outlook but also what might be called its theological contradictions. There was a call for neighbourhoods to unite and stand up against the drug dealers, muggers and violent intimidation. But it was balanced with reminders of the moral strength required to walk away from violence, a sort of combination of Old Testament solidarity with the New Testament cheek-turning.

As O'Shea admitted, when I later visited him at the school, he finds it difficult sometimes when young men in cars tell him to 'Eff off' for asking them to turn their music down. 'You walk away, but you walk away with an inner voice going, "I'd like to drag you out of that car" and I'm a 51-year-old professional with reasonable self-control. For a 17-year-old young man it's a big ask sometimes. It takes sophisticated interpersonal skills and great strength of character. And I think part of the challenge is equipping people to do that.'

One evening at Ladjua's house, I spoke to several of Kodjo's friends about confronting and turning away from violence. Bilal wondered if Kodjo might still be alive if he and his friends had stood up to intimidation at an earlier point. He outlined a sequence of events, beginning with an iPod that was stolen from one of the RFL boys by a younger boy. 'News gets around,' said Bilal, 'and everyone knew that he [the RFL boy] didn't do anything about it.' Suddenly the word was that RFL was a soft touch. Another of Bilal's and Kodjo's friends was hit by a brick, and Bilal was ambushed in the street by kids who were 'not really in the MDP, but associated to them'.

The RFL strategy, he said, was 'turn the other cheek'. Though some members had forsworn their previous involvement in trouble, others were drawn because, as Bilal put it, they 'were lovers not fighters'. Dwayne, a gentle teenager and another RFL associate, described the relationship between RFL and MDP as like that of 'geeks and bullies', with the MDP in the role of bullies.

I asked Bilal if black kids felt under particular social pressure to act tough. 'It's a way of protecting yourself,' he replied. 'Like the way a chameleon will change colour to blend in.' All of Kodjo's friends that I spoke with were fatalistic about the threat of violence: it was out there, appeared to be their attitude, you just had to manoeuvre round it. Seun, who is currently studying for A-levels, told me that he'd heard that some kids from Shepherd's Bush were out to kill him. When I asked him how this affected him, he said: 'Well, I avoid Shepherd's Bush.'

After Kodjo was killed, his friends and various young people turned a wall near where he was murdered into a kind of graffiti memorial, filled with messages like, 'Let's stop the senseless violence' and, 'I'm so sorry you had to leave. You had the potential 2 be someone.' There was also a big public funeral, complete with a glass hearse pulled by white horses, which hundreds of young people attended. The collective spirit underpinning the grief was anti-violence. But Bilal was sceptical about what it all meant: 'For five minutes, you're touched - "Oh, let's stick together" and all that rubbish - but some go back to their old ways. I see a lot of boys at Kodjo's funeral that said they're going to stop carrying knives, and now they've got bigger knives than the boys that killed Kodjo.'

Nearly all of Kodjo's close friends say that they want to honour his ambitions to be successful. 'At first I thought, "What have I got to live for?" just being immature about things,' said Cookie. 'But now I realise I don't think Kiz would have wanted that. And now I've started going to church and changed my life around and I'm in college, doing A-levels in law and English, and everything I promised I would do. I went through a rough patch to get to the top.'

Bilal's response, however, was less sanguine. 'It's been a darker change for me,' he said.

'I don't care any more. I don't talk to my mum any more. I'm like a Goth now. I'm not as patient or willing as I was before he died. There's no point having a car without an engine, and Kodjo was the engine.'

If Bilal is the most articulate, then Cookie, the girl in whose arms Kodjo died, is arguably the most remarkable of Kodjo's friends. She was not quite 15 at the time, and just a year older when, reluctant and scared, she gave evidence at the Old Bailey murder trial. Yet having witnessed such a traumatic event, and withstood the pressure of the court case, and even though she is still accused of being a 'snitch', she appears to harbour little bitterness.

She told me that in her opinion the MDP was not really a gang. 'There was a song called "MDP", Make Dat Paper. Just like RFL, Kodjo's crew, was Ride For Life,' she said. 'It was exactly the same.' And she also had compassion for the boys who were sent to prison. 'They're not dead,' she said, 'but they've suffered.'

She knew Boy C. 'I used to go to Tesco's with him to buy milk for his mum,' she said. Such incidental details expose the social bonds that have also fallen victim to Kodjo's killers. It was not just the murder of one boy, as tragic as that is, but an assault on the very notion of community. And when a community retreats from the assault, and becomes instead a collection of suspicious and untrusting individuals, the effect of the crime is multiplied.

Bilal was so dispirited that he wondered if American-style capital punishment might be the answer to gang murders. Cookie responded to this suggestion with an impassioned speech. 'That's why we've got gangs,' she said, 'because people think they're living in America. This ain't America, we ain't got ghettos. People are trying to come on as these Bloods and Crips. Listen, if you really want to go to America and have a look at a ghetto, then go over there, or to Jamaica. People call it their hood or their ghetto after the government have given them child benefit. Do they think they could be getting that in America? Or Jamaica?' Exactly what took place after Kodjo moved out of range of the CCTV cameras remains uncertain. There were as many as 42 witnesses to different parts of the attack, including two plainclothes policemen in an unmarked car. Most of them did not realise a murder was taking place and the evidence supplied by many was conflicting. It was said the gang shouted, 'Kill him! Kill him!', but Cookie insisted this never happened.

Some described a frenzied attack with multiple knives, baseball bats, fists and boots and a pitbull. The knives were seen being taken out from the knapsack that Tirrell Davis and Brandon Richmond passed to one another on the CCTV tape - a piece of evidence that probably secured their murder convictions. One witness said she saw Brandon and Tirrell take it in turns to stab Kodjo, and then hand the knife to Michel, who then also stabbed Kodjo, before handing the knife back to Brandon. However, Dr Fegan-Earl, the pathologist who conducted the postmortem, found only a single stab wound to the body, the one that penetrated Kodjo's heart and caused his death. There was a flesh wound on the left middle finger, and five other minor wounds on the left hand, but there were no dog bites and no indications that Kodjo had been subjected to a sustained attack.

Afterwards, the gang fled to Tirrell's grandfather's nearby house, where shortly afterwards they were arrested by police. An ambulance crew arrived and attempted to revive Kodjo in the street. It then drove to New Charing Cross hospital, where further attempts to save his life failed. He was pronounced dead at 6.15pm.

'You can spend months investigating this kind of crime and still not know why it happened,' said DI Wilkinson. 'Establishing motive is often important in murder cases. With Kodjo's murder, there was no real motive, just the triviality of a schoolkids' argument.'

Nine months before his death, Kodjo appeared on an MTV programme about knife crime. Wearing a white T-shirt, a gold chain and a backpack, he speaks eloquently and with quiet maturity on the subject. Most young men he knew who carried knives, he says, did so for their own protection. He doesn't think it is a good idea but he can understand why, owing to their surroundings or circumstances, they might think it necessary. 'Personally,' he says, in a soft, pensive voice, 'I wouldn't, because I'm not in that type of situation.'

He is against harsher sentences for knife possession, and also suggests that, while knife crime was growing, the media has exaggerated the problem. What, he is asked, could help combat the carrying and use of knives?

'More security,' replies the boy whose last half-hour of life was witnessed by a battery of cameras. 'Because if there was a lot of security and cameras watching people, they wouldn't have to carry knives around.'

• Andrew Anthony's book, The Fallout, is now available in paperback

Contributor

Andrew Anthony

The GuardianTramp

Related Content

Eyewitness 2008: Teenage knife and gun fatalities hit all-time high

Alexander Rose, founder of the STOP Campaign, on a year when 55 teenagers were murdered in the UK

28, Dec, 2008 @12:01 AM

Article image
The Observer's Martin Love on Kodjo Yenga, the boy he knew

Martin Love: Incredibly, appallingly, horrifyingly, I saw that the boy in Andrew Anthony's piece was my Kodjo

Martin Love

16, Nov, 2008 @12:01 AM

Article image
Brutal attack of goths Robert Maltby and Sophie Lancaster unite supporters around the world

On August 11 2007 young goths Robert Maltby and Sophie Lancaster were brutally attacked by a teenage gang ... a year on, Mark Hodkinson investigates the tragic death of the girl who dared to be different

Mark Hodkinson

02, Aug, 2008 @11:01 PM

Knife crime: Ben Kinsella's sister makes plea for witnesses to killing

Family says some witnesses have not come forward, while London mayor says all Londonders must fight knife crime

James Orr and agencies

02, Jul, 2008 @8:56 AM

Article image
No jobs, no hope, gunfights at your door – the tough streets that claimed Myron Yarde’s life
The stabbing to death of the aspiring 17-year-old rapper also known as MDot focused attention on the gang culture of south-east London, but others in the area are trying to offer frightened teenagers a brighter future

Mark Townsend

09, Apr, 2016 @11:04 PM

Article image
How Ben Kinsella's murder brought crime elders up against the young killers

Mark Townsend and Jamie Doward report on the clash between criminal cultures old and new

Mark Townsend

13, Jun, 2009 @11:01 PM

Knife crime: 'Doctors said I was a centimetre from death'

Journalist describes ordeal she underwent when she was stabbed after being mugged near her home

06, Sep, 2008 @11:01 PM

Article image
‘In Gloucester, young boys are carrying weapons’: how violence, drugs and abuse thrive when police fail
Reducing knife crime and domestic abuse is one of the steep challenges facing the Gloucestershire police, along with improving its own performance rating

Mark Townsend

26, Nov, 2022 @6:57 PM

Article image
School swap: Posh Wellington pupils meet under-privileged Burnley teenagers

What happened when the pupils at £9,000-a-term Wellington met under-privileged teenagers from Burnley? Elizabeth Day reports on a remarkable school swap

Elizabeth Day

04, Jan, 2009 @12:01 AM

Scenes from the battle to staunch flow of stab deaths

London hospital's A&E grants the Observer access to witness how medical staff cope with knife crime

Denis Campbell

06, Sep, 2008 @11:01 PM