I stop the car by the side of the road and turn the ignition off, but leave the radio on. Two politicians are tearing each other to shreds in a heated debate over whether Britain should join forces with America and start bombing the hell out of the Middle East in retaliation for 9/11.

When I think about the thousands of armed forces personnel who might one day be shipped off to fight if we ever go to war, it makes me think of George. As children, if we weren’t playing football and cricket together then we were pretending to be soldiers. He’d create army assault courses for us in the garden, with strawberry netting to crawl under and golf clubs to carry instead of rifles. We’d smear our faces in wet soil for camouflage and use an egg timer to see who could complete it in the fastest time. I would give it my all to try and impress him but didn’t care that he always beat me. I just wanted to be with my brother.

Some of my earliest memories are of that garden, of helping our father dig long, deep holes by the wall when we first moved in, of climbing the apple trees or playing hide and seek in the unused farmyard next door.

‘Six years left to go,’ George would remind me. ‘Then I’ll be old enough to join the army without Mum and Dad’s permission and I’ll never have to live in this house again.’

I hated it when he spoke like this. ‘What will happen to me when you’ve gone?’ I’d ask. He could never give me an

answer.

It’s George’s birthday soon and I try to imagine how he might look now. Do we still resemble one another? Maybe he’s still in the forces, his dark-blond curls now greying and cut military-grade short, his freckles perhaps fading with age. I picture him in his uniform, shiny medals with colourful ribbons attached to his jacket, rewards for successful tours of duty. But while I might no longer recognise him if he stood in front of me, I’d like to think that he is every inch the hero to others today as he was to me back then.

A little voice inside gnaws at me. That’s wishful thinking, it whispers. You know what happened to him. I shake my head to silence it. I once hired a private detective to try and locate George. But several months and a few thousand pounds later, there was no proof that he ever existed beyond my memory. Not even a birth certificate, even though I have one of my own. Sometimes I wondered if he was a figment of my imagination; if I’d made him up to make life at home bearable.

‘Are you okay?’ my passenger asks me. They’re sitting next to me in the front of the car.

‘Yes, why?’

‘You went quiet.’

I return to the present and contemplate the sprawling housing estate before us. ‘We are best to avoid places like that,’ I say.

I’m pointing to a Safeway supermarket and continue the lesson I’ve been teaching all morning. ‘It’s likely to have security cameras inside and out. They’ve also started attaching them to lamp posts in car parks. So it’s important we do our homework before we decide where to target.’

My passenger nods as if making mental notes.

‘It’s also vital that you adapt to your environment, which means you must plan what you’re going to wear. Don’t stand out from the crowd. I keep a completely different set of clothes for days like this. Never wear the

same outfit twice and always destroy what you’ve worn afterwards. Our own DNA is our biggest threat.’

On-the-job training, I guess that’s what you might call this. Although you won’t find the apprenticeship I offer advertised on a Jobcentre wall. I have years of experience to share with the perfect student. And I think I’ve found them.

‘If you’re targeting an estate then choose it carefully,’ I continue. ‘I avoid middle-class new builds and roads with large, expensive houses or ones that have two or more cars on the drive. It’s unlikely you’ll find who you’re looking for playing in their streets. Instead, choose areas with average or smaller homes – or even better, council estates. The more neglected the better. Look out for graffiti on the walls, overgrown gardens and discarded bin bags. If a tenant can’t be bothered to look after their house, they probably can’t look after their children either. And they are the ones who need saving the most.’

I turn the ignition and do my best to answer their questions as I drive to our second destination. I’ve only visited this area twice before, but I’ve put to memory certain places.

‘Why do you strangle them?’ This is just blurted, out of nowhere. ‘You’ve never told me.’

The question alone makes my fingertips tingle . . . the softness and pliability of their necks, the warmth of the blood flowing close to the surface, their palpitating, escalating pulse, their small, hopeless hands grabbing at mine . . . there is no feeling that will ever replicate it. ‘It’s clean, quite painless and you don’t need to rely on a weapon,’ I say instead. ‘And if you know what you’re doing, they can fall unconscious in seconds and stop breathing within just a couple of minutes.’

I park in a free space under a block of flats. Beer cans and smashed glass bottles are scattered about. ‘Weekdays are a good time to visit places like this,’ I explain. ‘There are plenty of children playing truant. Most parents either don’t

know or don’t care. So they make for successful targets because their absences aren’t immediately noted. But don’t be opportunistic. We must always be in control; always be in mind of our safety above all else.’

A young girl wearing tight jeans and a crop top draws our attention. She can’t be more than eight or nine years old, but she walks and dresses with the confidence of a teenager. I dismiss her, reminding my passenger not to choose anyone who might fight back. A boy on the opposite side of the road catches my eye next. He is small and rake- thin and lost in his own little world.

‘There!’ I say. ‘He’s the perfect example of everything I’ve been telling you.’ We exit the car and I look at my watch. ‘It’s 10.25 a.m. and he should be in school.’ We pick up the pace and I lower my voice. ‘His trainers are unbranded and falling apart and his football shirt has faded so it’s probably fake.’ The boy entertains himself by dragging a stick against a set of metal railings he passes. ‘He’s taking his time because he has nowhere in particular to go.’

We follow him to a park a little further down the road. The seesaw and slides have all been vandalised so he takes up residence on the one working swing. There is nobody else around. He is as vulnerable as they get. This boy is unloved and uncared for. He needs us to help him. An image of my parents briefly flashes into my mind. They are why I do this. To protect him from people like them.

‘Are you ready?’ I ask. When they nod, a rush of endorphins energises my body.

‘Can I watch this time?’ they ask as we exit the car. ‘Which part?’

‘When you kill them?’

I hesitate as I consider it and eventually decide against it, but without offering an explanation as to why. The moment is too personal to be shared. They don’t protest. Instead, we concentrate on moving in different directions

until they reach our target first. I watch from a distance as my instructions are followed.

This is all I have ever wanted, someone who shares my beliefs and who is committed to the cause. They have also helped me recognise how lonely this hidden part of my life has been until now. On paper I have everything I could ever need, but deep down, this part of me has been so isolated. I used to feel like the only person on earth who cares with such intensity about the well-being of others. But now I have found a kindred spirit who believes the same. I cross my fingers that this will be a long and fruitful working relationship.

Now I must focus. The skinny boy leaves with my accomplice and I know that, soon, I will have framed another mental picture. Only this time I will have someone else to share it with.

‌EXCERPT FROM CHANNEL 4 DOCUMENTARY WRONGLY ACCUSED. INTERVIEW WITH DS MARK GOODWIN‌

At what point during the investigation into the murders at Stewkbury did the accused appear on your radar?

It wasn’t someone we had a reason to be suspicious of so we didn’t dig into their background.

In retrospect, do you wish you had considered them a suspect earlier?

With the benefit of hindsight, there is a lot we could have done differently if we’d had the evidence. But there was nothing to suggest they were involved in the unlawful killings.

What were you focusing on at that point?

Identifying and interviewing known child sex offenders in that area at the time of the murders, as well as current and former neighbours and relatives of the deceased children. But the crimes were so historic and

appeared to end so suddenly that it was also possible the killer or killers could have died decades ago. It was an exhaustive, massive search with huge public interest and very few leads. And at that time we had no idea the case was about to expand into something broader than any of us could ever have imagined.

When did that happen?

The afternoon of the incident in question, when we were called to the warehouse following a fatal altercation.

Can you elaborate on what you mean when you say ‘the incident’?

When more bodies were discovered and the person we believe responsible was found with their throat slashed.