When Lee Lawrence’s son, Brandon, picked him up from hospital after a minor operation recently, Brandon thought he saw a car following them. Lawrence looked round and told his son he didn’t think it was anything to worry about. But then the car – which turned out to be an undercover police vehicle – put its siren on. It overtook them and did a hard stop. “I expected to see guns come out next,” says Lawrence. “I thought: ‘What the hell is going on?’ I got upset. My son was trying to calm me down, because I was thinking: ‘How could this be happening to my son?’”

Lawrence was 11 when his mother, Cherry Groce, was shot and paralysed in 1985 by an armed police officer during a botched raid on her home. Community fury over Groce’s shooting would spark a two-day uprising in Brixton, south London.

The officers, says Lawrence, said they had reason to stop the car – but it turned out to be unfounded and they went on their way. Lawrence was distressed. “Brandon said to me: ‘Dad, I know you’re upset, I know it’s disheartening for you, but this is the reality for us.’ And it really dawned on me. Part of me felt like, what’s the point? Questioning what I’m doing.”

In 2016, Lawrence founded the Cherry Groce Foundation. Part of his work there is to run training programmes for new police recruits and senior leaders, exposing racial bias, campaigning for greater diversity and for the power of restorative justice. He says his son being pulled over by the police was a sign that, “we have to do more. Don’t get complacent. There’s still a lot of work to do and you’re an integral part of that.”

***

We meet in the Brixton office of the foundation, a short walk from the beautiful memorial to his mother, designed by the architect Sir David Adjaye. In 2020, Lawrence published his memoir, The Louder I Will Sing, about the impact of Groce’s paralysis on her and her family, and their continued fight for justice after her death in 2011. In 2014 an inquest ruled that multiple and serious police failures contributed to Groce’s death. Lawrence’s book went on to win the Costa prize, and he is about to publish his second book, The Colour of Injustice, a history of the overpolicing and under-protection of Britain’s Black community. His mother’s story is part of it. “Whenever I do a talk, or work with the Metropolitan police, it’s important for me to say that my family’s experience is not a one-off situation. There are many other cases, and some may not have got the attention they should have. It’s quite powerful when you see it all in one place.”

It is. Lawrence identifies cases of racial prejudice, particularly in criminal justice, going back to the 1700s. He writes about Charles Wotten, the Black sailor who was chased by a mob through Liverpool and drowned as police watched, in 1919. He writes too about Mahmood Mattan, who was wrongfully convicted of murder and hanged in 1952. Dalian Atkinson was Tasered and kicked in the head by police during a mental health crisis when he desperately needed care in 2016. The multitude of stories of injustice, over our history until the present day, shows a pernicious pattern of racism. But it’s the contemporary statistics that are stark. Black people are seven times more likely to die after being restrained by police than white people, and are five times more likely to experience force during arrest. In some regions, Black people are nine times more likely to be stopped and searched, and Lawrence highlights that Black defendants are nearly 16 times more likely to face prosecution under “joint enterprise” laws, or being guilty by association. “I’m hoping that anyone who reads this will say: ‘OK, we can’t debate is it or isn’t it? It’s what are we going to do about it?’”

***

Lawrence says his childhood ended the day his mother was shot. On the morning of 28 September 1985, he was sharing a room with his parents and sister, when they were woken by the sound of their front door being kicked down. Groce leapt out of bed, Lawrence heard a gunshot and then saw his mother on the floor with a man pointing his gun at her. Lawrence screamed at him to leave his mum alone, and the man turned the gun on him. More armed men appeared, and dogs. The family realised they were police.

As a boy, Lawrence wanted to be a police officer. He loved watching cop shows – Starsky & Hutch, The Professionals. “I would look at those programmes and think: ‘I want to be catching the bad guys.’ There was something in me, I suppose, as a kid, that wanted to be that person to protect my community and do something meaningful and purposeful.” The police, he thought, stood for that.

After the shooting, Groce would spend two years in hospital. Lawrence and his sisters were split up into temporary care. “You’re going back to school, and everybody is trying to act like nothing has happened. And you’re thinking: ‘Can’t anyone see?’” Later, when Groce moved to a bungalow with her younger children (Lawrence is one of six), he became her carer while still a young teenager. Groce was 37 when she was shot. Before this, she had been an energetic woman who loved dancing. Now, she was in pain and could no longer walk. While she remained defiant, it frustrated her to be so reliant on her children.

Lawrence would make his mother breakfast, then take his sister to school before getting to school himself – usually late. “Not once again did anyone ask: ‘What’s going on? Can we support you?’ It was just met with punishment – detention, detention, detention – and then you become more rebellious, you just see school as another authority trying to suppress you.” For a time, he dealt drugs in his teens. “I had no idea about trauma and the impact it had on me, so I had all these feelings and anger issues and didn’t understand why.”

Throughout his teenage years, all his contact with the police was negative. When he was arrested for riding on the back of a friend’s moped, which turned out to be stolen, the police officer called him a “monkey”. He lost count of the number of times he was stopped and searched. It wasn’t until decades later, after his mother’s inquest in 2014, that Lawrence felt able to build a relationship with the police. The family was invited to the passing out parade of new recruits, and Lawrence decided “to challenge myself” and go. “It was only then that I started to experience a different side of the police.”

He had his first child at 21 (he would later have two more) and became an official carer for his mother after he left school, while also working in nightclubs and then as a black cab driver. He had therapy. “I still had the anger issues. I spent more than a year with somebody unpacking things, and it was only then that I realised what I was experiencing as an adult was linked to what I’d gone through as a child, all that trauma.” It helped him, he says, be mentally prepared to take on the battle after his mother died.

One of the themes that emerges in his book is how rare it is for the police to be held accountable. Does that embolden bad behaviour? Yes, he says. “We speak about culture a lot within the Met and if officers are doing wrong and not being penalised for it, and some are actually being promoted for it, what type of culture is that fostering? That it’s OK to do the job with no integrity? What I’ve realised, being on the opposite side, is that there’s a damage-limitation perspective from the Met as an organisation.”

After their mother died, Lawrence’s family were initially denied legal aid to fund lawyers at an inquest. A petition, which raised 130,000 signatures, helped to get that decision overturned. The jury at the inquest found multiple failures by the police. The Met apologised, but still didn’t accept liability – Lawrence and his family challenged that at the high court in 2016 and won. “Justice didn’t come to us in the formal way, in the way we should expect,” says Lawrence. “The next alternative was looking at restorative justice, because no one was actually held accountable for what happened to my mum. Nobody went to prison, nobody was penalised in any way.” The 1987 trial of Douglas Lovelock, the man who pulled the trigger, found him not guilty. “So we shifted focus: what do we need to heal and reconcile, and how can we have a positive impact on the organisation? How do we hold them to account, and how can we be involved in that process around reform and culture change?”

As well as compensation, the Met agreed to some of the family’s requests, but nearly a decade on, they are still to deliver on all their promises. One of these was to have an award in Groce’s name for an officer who shows exceptional community work. “Another thing we wanted to do was have something set up for people who have been traumatised as a result of bad policing. There are a lot of damaged people in our community, and they’re left with that negative impression of the police, and that spreads. One of the things we wanted to do was look at how we create a programme that supports people.”

He remains optimistic that there will be change. “They have to, and they have – maybe not enough, but they have. The book highlights some of that too, and I want us to take strength from that.” His hope is placed less on overall organisational reform of the police and more “on individuals … That’s where my energy is focused. I’m not saying that’s the solution, that’s part of it.” He points out that at current recruiting rates, it will take another 30 years before the Met reflects the community it serves. For Black officers, “in terms of climbing up the ladder, it’s very difficult. There is racism within the Met, and towards Black officers. I have seen that there are officers, particularly Black officers, who need more support, and more support from the community as well. I’m trying to look at how we do that.”

That his book is coming out as the UK struggles with anti-immigrant rhetoric, and far-right rallies, makes it even more necessary. “I just think: here we go again. We’re in the cycle. It’s propaganda that’s put out there to turn us against each other. What I hope is that we recover from that quicker before any kind of irreparable damage is caused.” If we don’t pay attention, he says, “history will repeat itself. To break that cycle, there needs to be more awareness of things that have happened in the past, so when we see those familiar patterns, we can act with more urgency around making change.”

Witnessing his son’s experience with the police earlier this year – and having a deeper conversation about it, during which Lawrence discovered that his son is careful to carry all his ID and paperwork with him whenever he is driving “so he’s not leaving anything to chance” – has intensified his mission.

After the acquittal of the man who shot her, Lawrence remembers his mum saying the police were a force, and you can’t beat a force. But he never accepted that. It’s the same when he sees the impact on his son. “I understood why she said that. For her it was about survival. She had to focus on raising us children. That battle wasn’t for my mum. It was my battle, to fight for her. She needed to fight to survive, and I’ve had to fight to make sure that what happened to her was acknowledged, and that we use that now for change.”

• The Colour of Injustice: Stories of the Fight Against Prejudice and the Law is published by Little, Brown (£22). To support the Guardian buy a copy at guardianbookshop.com. Delivery charges may apply.