The gunmen then ordered everyone into the flat where Jason's mother and younger sibling slept. His friend, David, tried to slam the door shut on their assailants. Shots were fired and one bullet ricocheted around the corridor. The next hit David in the leg. The bullet, Jason believes, was meant for him. For a teenager who had once carried a gun himself, it was a wake-up call.
"It is all fun and games," he told The Independent, "brandishing a gun, taking pictures of it, until you see people getting shot, until you see the blood. Then it is different. I don't want to see a bullet in someone again."
This was not a battle between drug dealers, but revenge for a fight at school. The gunmen had made threats three days earlier because they thought a boy who had beaten one of their brothers was in the flat.
"We went to the police. They were not taking us seriously," says Jason (not his real name), now 18. In his baseball cap, diamanté earring and tracksuit, he looks every inch a product of his background.
The son of drug dealer, Jason was arrested seven times for stealing in his younger days. At the age of 14 - already a father himself - he was expelled from school for selling cannabis.
He says it is for the sake of his four-year-old son that he has changed. "I don't want my son growing up thinking his dad is a killer, a gunman. I want to be a proper role model," Jason says.
These days he goes to schools to talk about guns and works as a "peer mentor" for a Peckham-based charity called the From Boyhood to Manhood Foundation. It believes youngsters caught up in violence do not need lectures. Instead they need to learn from people they understand.
Through education and self-help programmes, children with a troubled history are taught that respect can be earned in other ways than through having a gun.
"I speak to the young ones," Jason says, "and ask them where they want to be in three years' time and they say 'on the road', that means on the street selling weed. They want that lifestyle.
"It is a vicious circle. They get a £5,000 watch and then someone robs them." Jason estimates that 80 per cent of his peers are in gangs and three out of five have guns. He has known so many friends who have been shot or stabbed that he cannot put a figure on it.
Jason now has maths and English GCSEs and is interested in a writing career. But he still remembers the moment his mother, having witnessed his descent into violent crime, appeared to have lost hope for him.
"I was in the police station and I saw a look in my mum's eyes, 'Is this the road he is taking?'. She was crying, scared. I just thought 'Fuck this. I have to look for a different road to take'."Reuse content