It was 6.30am on a Saturday when Anthony Moo-Young’s phone rang and a voice told him his sister Cherry had been shot. It made no sense – “I said, ‘What are you speaking about?’” – but the caller just told him to get himself down to Cherry’s house in Brixton as quickly as possible.

The date was 28 September 1985 and, over the next few hours and days, Brixton was to erupt in violence between the local Afro-Caribbean community and the police, in the wake of Cherry’s shooting. She was 37 years old, a mother of six, and she had been shot by a police officer in her own home. They’d been looking for her son, who wasn’t in at the time. In the TV footage from those days, Tony is impressively, eerily calm. He could almost be a doctor, so clearly and precisely does he describe the injuries Cherry sustained – injuries so severe that she would be paralysed for the rest of her life.

Today Tony is back in Brixton and we are chatting in a house just half a mile from Cherry’s, on what was once the front line in one of Britain’s most serious race riots, events that left one person dead and 53 others injured. And Cherry’s brother is the same calm, centred presence. But today he’s no longer Tony Moo-Young – he’s Mooji, a spiritual teacher and guru with hundreds of thousands of followers across the world, people drawn to his quest to discover secrets to a more meaningful, less troubled life. A disciple of an Indian teacher called Sri Harilal Poonja, Mooji holds retreats, gives talks and runs an ashram. His philosophy is simple: if we connect to our true nature or self, we can live a true and meaningful life. His events pack in the crowds, and he performs what looks a lot like a public therapy session, homing in on individual issues and giving feedback. Meeting him, you can see his appeal: he’s one of those people who focuses in on you, making you feel like you really matter. To sit with him, they say, is to be at peace.

It was an explosion. I saw the first bottles being thrown

Many people who are fans of Mooji’s philosophy have no idea about the role the Brixton riots and Cherry’s shooting had in his transformation from street artist to spiritual leader. Back then, Moo-Young was 30 years old, and was supporting his wife and young children by working in central London drawing caricatures. “I would set up outside the National Gallery,” he says. It was a precarious existence, but his work was popular. Managers at Shell, where his then wife worked, often asked to draw caricatures of staff who were leaving.

Brixton was still quiet that morning, as Moo-Young hurried to Cherry’s house. The pair were extremely close. They’d been separated as children because Moo-Young had remained in Jamaica when his mother came to the UK, leaving him with his father when he was just a year old. He grew up in an extended family where everyone looked after everyone else – “I didn’t even know whose father was whose” – and his mother’s place was taken by her cousin, who also became his father’s lover and had more children.

But after Moo-Young’s father died suddenly when he was eight, his life in Jamaica got harder – he was cared for by an uncle who was much stricter than his dad – and after his mother, one of the Windrush generation of immigrants, returned to the West Indies for a visit, he decided to follow her back to the UK. He was a teenager by then, and had never been on a plane before – and his first attempt to get in failed as he didn’t have the right papers, so he was detained overnight and sent home the following day. “It was a very strong experience,” he says. “It helped me not to take things for granted.”

But on his second attempt the papers were in order and he joined his mother in Brixton, where he remembers being embraced into the “big cushion” of the community. Everyone was very warm, particularly his sister Cherry, who lived close by. “She seemed like she had never really left Jamaica,” he remembers. “She was so rawly Jamaican. I would spend time in her house, she would play music and she was so easy to be with.”

There were two police officers standing outside her door that morning when Moo-Young arrived but, he says, they seemed quite relaxed. Cherry, he learned, had been taken to hospital. She’d been in bed when police broke the door down and crashed into her house, searching for her son Michael who had a history of petty crime. He wasn’t at home, though the other children were. They were woken by the commotion, and then heard the shot.

Moo-Young headed to St Thomas’s hospital where Cherry was being treated. She was conscious, but clearly severely injured. A few hours later he returned to Brixton, where journalists were now gathered on Cherry’s doorstep, and felt “a strange vibration” in the neighbourhood. “I didn’t like the sound of it… I could see there were a lot of people on the road.” He went down to the police station, where there were already police on horses in riot gear. He asked one of them if there was anything he could do to help cool the situation, but was told it was too late for that. On his way back down Brixton Hill he heard shouts. “People were saying they’d heard on the news that Cherry Groce was dead,” he remembers. “It was like an explosion. I saw the first bottles being thrown… I got away from there.”

Over the next few days, as Brixton erupted into chaos and flames, Moo-Young tried to be a voice of appeasement. “I was saying, ‘We don’t want what’s happening. We’d prefer people to hold back.’ The violence was bad, people should calm down. It was a peaceful appeal and it won us a lot of support – we weren’t asking for vengeance.” Within a few days he was being interviewed on TV by Jeremy Paxman, and delivering a petition to 10 Downing Street. “My days as a street artist were over,” he says.

Instead, he made designs for a stained glass window on the Tree of Life for St Matthew’s Church in the centre of Brixton, and exhibited alongside other Jamaican artists. Around the same time he met a mystic whose friendship was to have a profound impact, and discovered the writings of Indian gurus. Cherry, now home from hospital and installed in a specially adapted house in Crystal Palace, paid him to paint murals on her walls. Afterwards he travelled to India in search of the temples and thinkers whose writings were already beginning to have a big impact on his life. He kept in touch with Cherry, who was being cared for by her family.

He travelled for a year, returning to the UK in 1994; he had no job, but eked out a living selling incense. As a sideline, he enjoyed sharing his “thoughts for the day” – snippets of wisdom that he wrote out on paper which he rolled up and put inside straws from McDonald’s. The “thoughts” were light but meaningful: “God gives you bread. Don’t ask for toast – make it!”; “Why are you out shopping for new shoes when you are given wings to fly?”; and “In whatever situation you may be, right there is a doorway to your innermost Being.”

Talking one-to-one, sharing his innate wisdom, the man now reborn as Mooji realised this was his calling. “What I enjoy doing is creating the space for contemplation – it comes from my artistic background,” he says. Today he’s based in Portugal where he set up his ashram in the southern hills, and welcomes followers from around the world.

And what of Cherry, the sister who changed his life? She had been in bed when she was shot, presumably having been mistaken for her son: Douglas Lovelock, an inspector with the Metropolitan police, stood trial in 1987 for inflicting unlawful and malicious grievous bodily harm, but was acquitted. Cherry’s life, meanwhile, was peppered with continuing complications from her injuries, and she eventually died of kidney failure in 2011, at the age of 63. Despite all she suffered, says Mooji, she never bore anyone ill will or blame. “Sometimes she got frustrated, but her heart was soft and she was always kind.” In 2014 an inquest found her death had been directly linked to the shooting; and it’s entirely in character with the zen-like personality Mooji is that he says he never feels anger about what happened. “Cherry once said to me that in some ways it was a good thing, because it gave her a lot of time to reflect on her own experience,” he says. He acknowledges the role her tragedy had in changing his own story; and his passivity seems part and parcel of his philosophy of acceptance, a way of playing out his belief that it is in sitting with the realities of life, rather than fighting them, that we all find the best way forward in our lives.

Vaster Than Sky, Greater Than Space: What You Are Before You Became, by Mooji is published by Coronet at £18.99