At 6.55pm on 25 July a silver moped careered down Denmark Road in Camberwell, south London. The pillion passenger appeared to be in a terrible state; slumped forward, he was barely able to hold on. As the scooter neared a junction, it screeched to a halt. The passenger slid sideways off the saddle and on to the road. Shouting for help, the rider sped away. “The boy was hanging off the back, then he came off and was left right there, on the road,” said Nayan Patel, 61, who owns a newsagent’s close by.

Latwaan Griffiths, 18, was taken to hospital. At 12.22am the next morning he was pronounced dead. Griffiths, who had been stabbed twice, would have turned 19 on Thursday. His death was recorded as the 88th killing in London this year. Barely more than a month later, the number of violent deaths – stabbings, shootings and vicious domestic attacks – being investigated by the Met is reported to have reached 100, the fastest rise for a decade.

This weekend for the Notting Hill carnival, metal detector arches have been installed for the first time since the event began in 1966.

Faced with the many reasons for the London bloodshed, the government seems impotent, critics say. The police, compromised by falling officer numbers and budget constraints, are accused of being incapable of making the capital safe. Those who live on the south London estates, hit by the most recent rise in violence, say they have been abandoned by the government.

Griffiths fell from the moped a 30-second drive away from King’s College hospital, which serves Camberwell and the surrounding streets, where a wave of attacks have taken place, including the stabbing this month of four teenagers on the Elmington estate. A 15-year-old remains in hospital with life-changing injuries.

The trauma theatre in the accident and emergency department of King’s, where doctors tried to save Griffiths’s life, had treated scores of youngsters for stab wounds in the preceding months.

Fresh data from the hospital for the year so far shows that 345 people aged between 11 and 25 have been referred to youth workers after being stabbed or seriously injured. Of these attacks, more than 150 cases involved a “weapon-enabled assault”, and a surprisingly high proportion – 40% – of the victims were female.

Arrivals most commonly begin after 4pm, with most victims treated, like Griffiths, between 6pm and 7pm.

Lucy Knell-Taylor, a youth worker for the charity Redthread, who works alongside the trauma medics at King’s, said that most referrals were “normal kids” caught up in violence, although the area’s pockets of deprivation and a lack of opportunity seduced some into criminality.

“Much of this violence is born out of poverty of resource, poverty of experience. If you think you’re never going to be able to own a home, never get what young people refer to as a ‘leg’ – a legitimate job that pays decent money – if you believe you haven’t got much of an alternative, you might get involved in criminal activity,” said Knell-Taylor, who has helped 168 seriously injured young people since starting at Redthread almost two years ago.

Griffiths was a drill music rapper – street name Splash Addict – for the Harlem Spartans, one of the patchwork of gangs that populate Camberwell’s estates.

The street where he fell marks the western boundary of the Crawford estate, turf of Moscow 17, one of the largest gangs in the area and affiliated to the Harlem Spartans.

Six days on and a quarter of a mile north from where Griffiths came off the moped, the drill rapper Sidique Kamara, known as Incognito, was fatally stabbed on the Brandon estate. His friend Rhyhiem Ainsworth Barton had been shot dead weeks earlier on the same street.

Just beyond where they were murdered lie the southern reaches of Kennington Park and the six towering blocks of the Brandon estate, home to Griffiths and base of Moscow 17.

On Thursday morning the estate’s under-15 football team, Unity FC, were preparing for the new season. Their coach, Peter Baffour, was putting his players through their paces, but looked distracted.

Pointing to the six-storey flats to the south, he said: “We’ve had three stabbings there. One of our players, Abdul, who was 17, died a couple of years ago. Another was shot.” But Baffour added that sport had kept his players from the gangs because it kept them off the streets. One of Unity FC’s star players, Daryl, 15, said: “Football gives us ambition. There’s not much else to do.”

Facilities are sparse on the Brandon estate. Unity FC train on the park all year round because the council charges £60 an hour for its AstroTurf pitches. The estate’s youth club closed years ago, one of more than 80 to have shut in London since 2010.

Facebook Twitter Pinterest Peter Baffour coaching Unity FC in front of the Brandon estate. Photograph: Andy Hall/The Observer

Junior Smart, a former drug dealer for several south London gangs, said the area’s network of “safe havens” for adolescents had been dismantled. Now, Smart warned, youngsters had nowhere to hang out, instead forming groups for protection that could easily be folded into an estate’s existing gang hierarchy.

Smart, sentenced to prison for 12 years in his mid-20s after being caught in possession of several kilos of crack cocaine, said: “At one youth club in south London we had 120 kids every night– it was oversubscribed. Now they end up on the estates.”

Compounding the scarcity of safe spaces is a lack of police. Camberwell police station is open for a total of just three hours during the whole of August. The local Camberwell Green ward police recently went down to two officers responsible for day-to-day policing and a community support officer.

Elena Noel, a Home Office adviser, said the reduction had emboldened gangs to “occupy a public space that police have stepped back from”. More pertinently, she said, the absence of security had forced children to take safety into their own hands: street justice prevails. “If police can’t make them feel secure, they turn to the street justice system, which is carrying a knife, buying into thug life.”

Knell-Taylor said that a sense of the absent state was behind much of the violence. “A lot of what drives violence is fear – young people who are scared and traumatised. If you think everyone else is carrying a knife, it’s not a wild jump to think, I need to carry something. It’s about kids who rationally feel that if they carry a weapon they can limit the harm done to them.”

Smart, who now runs a gangs project for the St Giles Trust charity in Camberwell, said: “Kids are telling us there are more reasons to carry [knives].”

Loss of faith in the police means witnesses are reluctant to come forward and intelligence declines. Solving crime becomes harder.

Facebook Twitter Pinterest Former drug dealer Junior Smart on the Brandon estate: “Kids are telling us there are more reasons to carry.” Photograph: Andy Hall/The Observer

“The wall of silence is even higher now because of the fear factor gripping the community. Even if they decide to give information, they must think of their nearest and dearest – they could be subject to retribution,” added Noel.

Griffiths’s family have blamed this wall of silence for a lack of progress in the police investigation into their son’s murder. The id entity of the moped rider is unknown, as is the location of Griffiths’s stabbing. Despite several arrests, no one has been charged.

Leroy Logan, a former superintendent in the Met who spent 30 years in the force and retired in 2013, said that faltering intelligence, a reliance on misinformed assumptions and a sharp reduction in the number of analysts to decode tip-offs and clues meant the force was struggling to subdue youth violence.

Illustrative, he said, was the fact that many of the most serious crimes were not being solved. “The murder clear-up rate used to be over 90%, now the clear-up rate is just over half – that sends a signal to people that there is a good chance they can get away with it.”

A t a boisterous meeting on youth violence last Tuesday evening in Brixton, which borders Camberwell, the London deputy mayor for policing and crime, Sophie Linden, said that the borough of Croydon had analysed 60 cases in which a young person had either been murdered or seriously injured. Not a single one had been in mainstream education.

Stacey Telfer, the manager of Unity FC, believes state education is itself so deficient that many young people from the Brandon estate are effectively isolated from the legitimate economy. “We’ve got year 4 and 5 pupils who can’t write their name or address. Some can’t even write.”

Gavin Hales, a criminologist and former consultant for the Metropolitan police, said gangs offered those with poor qualifications instant cash, status and camaraderie, as well as a sense of family. “There are very low entry costs – it’s cash in hand. There’s a seduction about it because it’s ready money.”

Facebook Twitter Pinterest Sidique Kamara. Photograph: PA

During the Brixton debate, the ease with which gangs are able to recruit was highlighted by the concept of “chicken shop grooming”, where established gangland figures entice “youngers” by offering free food in local fast-food joints.

Telfer is acutely aware of such methods: “We can’t leave the training sessions for lunch because you never know who will turn up. You’ve got to keep an eye on these kids at all times.”

Other factors are harder to control. Last week Nike was forced to remove a full-face balaclava from its website after being accused of targeting gang culture for profit.

Another fashionable entity is drill music, performed by young men such as Griffiths. It has been accused by the Met of inciting violence, but Knell-Taylor believes drill should be considered as merely soundtracking the experiences of youths in deprived neighbourhoods. She said its sinister tone articulated many drill rappers’ feelings of marginalisation. Much of the posturing, she added, stemmed from fear.

“A lot of drill is testimony, young people talking about being scared, about being brutalised, about spending time in custody, about being let down by adults and olders,” said Knell-Taylor, who comes from Kennington.

Logan dismisses the Met’s demonising of drill as disingenuous and a sign of the force’s desperation as it contemplates a crimewave it cannot control. “Drill videos can each attract up to a million views. Do you see up to a million people going out and stabbing people? They are just co-factors,” said the ex-policeman.

The violence, said Hales, should also be viewed through the prism of life outside of the mainstream economy. Violence can be a highly effective means of developing status and growing an illicit business, but masculine identity can be acutely fragile and sensitive to supposed slights, he said.

“People are vulnerable to predation by others. This can create an acute sense of anxiety about status and reputation and can mean overreacting to perceived slights in other settings.

“You and me might have a job, a house, a car. If someone does something you perceive as disrespectful, you can live with that. If I don’t have those things and I’m involved in illicit activity, my anxiety about my sense of status is heightened. That raises the stakes,” said the criminologist.

Smart believes the mindset among young people caught up in the current violence – serious youth violence in London increased by 9.6% in the year to April – has altered, another reason why the issue is escalating.

Facebook Twitter Pinterest Tributes at the site where Sidique Kamara was fatally stabbed. Photograph: Andy Hall/The Observer

“I was speaking to a kid about a month ago and he was saying, ‘It’s kill or be killed out here’ and I was like, ‘You’re barely 15, how can you say that?’ My mentality was different when I was involved [with gangs], that if you’re not strong enough you’ll become a victim.”

Mental health needs among young people should, according to Noel, also be factored into the debate, both as a symptom and cause of youth violence.

“Adverse childhood experiences in the home, on the street, in school or on social media will lead to undiagnosed, occasionally unsymptomatic, psychosis and trauma. And if you get the physical trauma on top, you’ve a ticking timebomb.”

The government’s response to the crisis has been to establish the serious violence taskforce and youth violence commission.

Already experts believe the policy implications of tackling such issues are too vast. “It’s extremely difficult for government to come up with a concerted response because you’re talking about changing the economic realities for young people in these communities. The policy implications are lots more money. It’s a long-term public policy problem that nobody has found a solution for,” said Hales.

During last week’s Brixton meeting, the Streatham MP and former shadow business minister Chuka Umunna said that for a young person on an impoverished south London estate to succeed in building a booming business from scratch was practically impossible.

Among those in the audience was Shanelle Webb, 21, who had arrived in hope but left nonplussed. “Too many buzzwords, typical politicians. They have no idea what’s going on out there,” she nodded east, towards Camberwell, towards Denmark Road.