On 23 March 2015, Shirley (not her real name) sent an email to her MP with the heading: “PLEASE HELP ME SAVE MY SON!!!” She described how the behaviour of her 13-year-old son, Sean (not his real name), was “[deteriorating] rapidly, involving himself with the wrong crowd” and her fears for the impact this could have on his siblings. She detailed how she had enrolled herself in parenting classes, consulted with social workers and psychologists, sought referrals for mental health assessments, requested to move him from his school and asked for help to move her family out of London, but felt she was getting nowhere.

She ended the email: “All I want is for my [children] not to become another statistic and would like all the help possible to stop this from happening.”

A few months later, she warned a meeting of social workers in Brent, the London borough where they lived: “If we don’t do something, he’s either going to end up dead or someone’s going to end up in a body bag.”

Two weeks ago, Sean, now 15, was sentenced to 14 years in prison for stabbing to death Quamari Serunkuma-Barnes, also 15. Sean had been waiting near Quamari’s school in Willesden, north-west London, with a knife on 23 January; when he saw Quamari leaving school, he started to chase him. Taller and faster, Sean caught up with Quamari and stabbed him three times, including one fatal blow that pierced a rib and punctured a lung. Quamari died that evening, the fifth of 26 children and teenagers to have been killed by knives in Britain this year. The Guardian has been tracking their deaths as part of Beyond the Blade, a year-long project that attempts to understand the scale of the issue and explore the underlying issues.

After Sean was convicted in July, I wrote: “It is difficult to know what justice looks like when one 15-year-old is dead and another is on trial for their murder … One thrashes about, mostly in vain, for an institution, service or agency to blame; for an intervention that could have helped or a moral safety net with smaller holes that might have caught him.”

It turns out, in this case, such a search would not be in vain. Shirley, 33, can document, in painstaking detail, requests for help that either were not answered, were not met or where the response was inadequate even as she warned of the possible consequences.

There’s no saying if this tragedy could have been prevented. What is clear is that more could have been done to try. “My son is totally responsible for his actions,” Shirley says. “But the preventative measures that should have been put in place were not there. I’m not blaming Brent [council] to say: ‘You held my son and made him do this.’ Ultimately he’s responsible. Ultimately there’s a family that is broken.”

For the most part, fatal knife crime is reduced to a crude morality play, in which the young perpetrators are all but invisible. Abstracted from parents or community, we meet them in the dock defined by their crime. They are not children who have killed but killers; not people who have done something monstrous, but monsters. They stand reduced to this one act: they killed a child. Their anonymity protected by law, we do not see their pictures or hear from their parents. By the time the trial is over, we have no idea where they have come from, why or how, only where they’re going – prison. Without face, family or friend, they are not children, they are cautionary tales.

Quote from Shirley Photograph: Guardian Design Team

But in order to heed the caution in these tragic crimes, we must first restore the humanity of those who commit them. Failing to do so is not only morally problematic, it is counter-productive. The best chance we have of sparing the next child from an early death is finding out why the last one died. There are lots of lessons. But none can be learned if they do not start from the fact that this murder was committed by a boy, not a metaphor.

Sean has a narrow, handsome face and a lanky frame. From the words of his mother, his barrister and the judge, one builds a picture of an impulsive teenager with a keen sense of grievance, as desperate for affection as he is clueless how to earn it. Every day of the trial he would wrap his long arms around his mother and, whenever he could, touch his barrister’s hand before he was led away. Lost, angry and responding intensely to slights, real or imagined, he has struggled to connect actions to consequences, and his sense of vulnerability seems intimately connected to his episodic bursts of violence.

Much of this is standard teenage fare – only with far greater stakes than most teenagers are used to. Shirley has done her best to guide and protect him from the cruelty of the streets, the negligence of the state and, for much of his short life, from himself. Moments after Sean was convicted of murdering Quamari, I saw her emerge from court and bump into Quamari’s father, Paul Barnes. Both tearful, they clung to each other.



“I’m sorry,” he told her. “I just wanted justice for my son.”

“I’m sorry,” she said. “I’m sorry.”

“I wish I could have spoken to him more,” she tells me, two months later. We have peered into three coffee shops looking for somewhere not too crowded, so she might cry and not make a scene, and settled on a cafe in Morrisons. “But at the same time, what could I say? I’m probably the last person he wants to see. That’s why I have to give him a massive amount of credit for actually taking the time to say something to me.”

Every day of the trial, she travelled to the Old Bailey wondering whether her fellow passengers would move away if they knew where she was going and why.

“Whenever [Sean] was judged – and he was judged a lot as a child – I was judged. But I had to sit with him through that. I wouldn’t have it any other way. And that’s one of the reasons I didn’t want anyone with me. Because I didn’t want them to feel they were being ridiculed. That they were being judged. This is a burden I had to bear on my own.”

Shirley raised Sean on her own for most of his life. She separated from his father when he started dealing drugs, but his father and paternal grandmother played an active role in his life. A happy kid, he watched Finding Nemo so often that Shirley knew the film by heart. Then he graduated to The Lion King, deciding early on that he wanted to be a vet. Shirley is religious and took him to church. A very active child, in later years he became an accomplished athlete and footballer who gained the attention of professional scouts.

When Sean was in primary school, his dad was deported. This was the first time Shirley noticed Sean getting angry and withdrawn. She tried to get help from Child and Adolescent Mental Health Services (CAMHS) at the time, but was told he didn’t meet the threshold. At secondary school he seemed to be doing well academically, but before long he was expelled after an altercation with a teacher. From there he was sent to a Pupil Referral Unit, which Shirley considered not an alternative academic environment but a dumping ground for children with behavioural challenges. She tried to get him moved.

“This is not the environment for my child,” she told them. “I know my child. If he is around people who are bad, he’s going to want to be the best at being bad. If he’s around good people, he’s going to want to be the best at being good.”

Soon Sean was getting into trouble with kids she thought were a bad influence. This was when Shirley enrolled herself in a parenting course and requested help to be rehoused outside London, where her son might find a more positive peer group. She was supported by a Safer Schools police officer working with Sean, who wrote: “It would be highly beneficial ... as a preventative measure and a chance to give him and his family a fresh start.”

The request was denied. Shirley had him assessed again by CAMHS, but she says that after a 20-minute interview he was declared fine. “I’m not a professional,” she says. “But I don’t think you can assess in that short space of time.” Unable to move her family, she took the difficult decision of moving Sean after he and a friend were threatened with their lives unless they returned some stolen goods. She put him in care, asking for him to be placed outside London, away from temptation. Instead, he remained in London and started getting into more serious trouble, including street robberies. She complained and lobbied. Emails received no response. It was around this time she first appealed to her MP to HELP ME SAVE MY SON!!!!. Further emails to Brent council over the next couple of years carried subject lines including “I HAVE HAD ENOUGH” and “UTTER DISAPPOINTMENT”.

“Every time my son gets in trouble it’s for something more and more sinister,” she recalls telling them in one meeting. “So you’re waiting for something to be broken that can’t be fixed in order to come to some kind of resolution. I’m asking you to prevent the item from breaking.”

Brent council says: “An independent multi-agency review is now taking place. The council, along with other agencies involved, has been participating fully in this process to help us agree how lessons can be learned. ... it would not be appropriate to comment further on any aspect of the case until this review is concluded later in the autumn.”

The way Shirley sees it, the problem was not that Brent council did nothing. It’s that what it was doing wasn’t working and, she felt, lacked urgency and focus. “The local authority failed him,” his barrister told the court during sentencing. Eventually, Sean was moved to one care home in a rural area in the north that he kept running away from and was then moved to another where he was racially abused and physically retaliated. He was eventually returned to London. Shirley asked for anger management classes for him, but didn’t get them, and they were offered family therapy only when he was living four hours’ away. On the day of the murder, she says, she called Brent to express her concern that he was not getting any educational provision.

“If I was in denial that would be one thing,” she says. “But if you’re open and you’re going to the foot of the cross where the mercy’s supposed to be, where they’re supposed to help you and give you those multi-agencies to come into your life. If you’ve gone there and they can’t turn around and help you but say: ‘It cannot meet the threshold’ or ‘The budget is not there’, then what are you supposed to do?”

At one point Shirley asked for Sean to be put in a rehabilitation unit that he wouldn’t be able to leave. But, she claims, Brent said they thought the request would be denied by the courts because it would take away his freedom and, even if he could have a place, this would be too expensive. “But I didn’t ask them how expensive it was,” she says, tearing up. “Can you go to Quamari’s parents now and give them £10m or £100m for them to feel better? You can never fill that void because their child is gone.” Two months before the murder, she asked again.

Quote from Shirley Photograph: Guardian Design Team

In the TV series Six Feet Under, Brenda tells her undertaker boyfriend: “You know what I find interesting? If you lose a spouse, you’re a widow or a widower. If you’re a child and you lose your parents, then you’re an orphan. But what’s the word to describe a parent who loses a child? I guess that’s just too fucking awful to even have a name.” When one 15-year-old is dead and another is in prison, there is no need to compete for sadness. There’s more than enough grief of every kind to go around. On the day of the sentencing, an impact statement from Quamari’s mother, Lillian Serunkuma, was read out. It was addressed not to the court, but to Sean. “You have a future regardless of your sentencing. You stole our son’s future when you felt entitled to take his life for no reason other than to gratify your own self-worth and ego, which evidently is misplaced and nonsensical,” it read.

“You are a child but your actions were pure evil and for this we cannot imagine our words will do anything to make you see the hurt and pain you have caused ... Your actions were indefensible and it should have been recognised and flagged up, the danger you are to yourself and to the people around you.”

The sentencing would bring one more shock. Less than an hour before the court sat, the judge received Sean’s confession, which his barrister read out in open court.

Nine days before the murder, Sean explained, he had been beaten up by members of a gang. When he went to visit a friend, he was offered not a salve for this adolescent wound, but salt. His friend’s mother said: “I’ve never known you take a beating,” while his friend asked whether he would “take the violation”.

That same friend gave him the knife, ski mask and gloves. Sean took them to his foster home and left them under his bed. He nursed the grudge for more than a week.

One rival in particular kept mocking him online, taunting him as Sean rapped on social media just a couple of days before the murder, calling him a “wasteman”.

What emerges is an account of a boy in an almost semi-delirious fugue state on the day he killed Quamari – his mind racing from grievance to revenge, incapable of finding solace or calm. “When I woke on 23 January, I felt frustrated and vexed. I still had a knife ... I called my nan [his father’s mother] ... I wanted to see her because I thought that if I saw her she would calm me down. I was angry and upset.” He tried to visit his nan, but she wasn’t in. “I went to the school. By then the words about taking the violation were ringing in my ears.”

Sean planned to confront his rival but saw Quamari first. Quamari had nothing to do with any gang or the beating Sean had suffered. But Sean recognised him and associated him with an incident in which he had been humiliated two years earlier.

“I am telling the truth now for Quamari’s mum and dad,” Sean concluded. “I had a dream that I was in their house and allowing them to speak to me for me to tell them what happened and that I am sorry. I am sorry. I didn’t mean Quamari to get so hurt. I’m not a murderer. I’m not a wasteman. I didn’t want him to die. I wish I’d told the truth before. I listened to someone close to me I shouldn’t have listened to. I didn’t trust anyone else. They always let me down. I want to have a different life, but I don’t know how. I am trying and am SIP (serving in peace). I am doing well in education and got an award last week. I am sorry.”

Shirley says he seemed lighter after the conviction. “Mum, I’m tired of this life,” he told her. Finally he has anger management classes and a more regular education. A few days after the murder, Shirley and her family were finally moved out of London. The night before we met, Sean called home. “Mum, I’ve got some good news for you,” he told her. “They’ve put me forward for my GCSEs”.

And with this, Shirley cries again. “I’m so happy for him. But on the other hand, when I think about the background, I just crawl back in my shell. For the longest time I couldn’t even bring myself to say Quamari’s name. I didn’t even allow myself to mourn Sean’s situation because I didn’t think I was worthy of feeling anything because my child was still here. I had to get myself out of that mode because I was about to break down. It’s still a loss for me as well.”

And so Shirley is destined to hover, between anger and grief, regret and recrimination, asking and answering the three essential questions that act as pillars for her tender emotional state, as though in an incantation, even as they offer neither closure nor comfort. “Is he responsible for his actions?” she asks, rhetorically. “Yes. Did I try everything I could? Yes. Were we failed? Yes.”