I live in the Scottish Highlands where, last year, I read about a lone hiker who disappeared. Literally. He went off hill walking one day and never returned. The story made a few paragraphs in a local paper, that was it. Beyond a few social media groups, his disappearance was barely noticed. No one was interested. And his immediate family aside, no one seemed to care.

It made me wonder why some missing persons cases receive so little interest, while others make huge headlines.

So I began to look into the phenomenon and even as a former police officer of 25 years, I was startled by what I found.

On average, someone goes missing in the UK every 90 seconds. Yes, you read that right. Every minute and a half, someone disappears. That’s 170,000 people a year reported missing – a truly staggering number.

Fortunately, the vast majority return fairly quickly, within hours, days or weeks. But national statistics reveal nonetheless that there are more than 5,000 long-term missing people unaccounted for. Another astonishing statistic.

And all these people have a story.

They all have family, friends and colleagues, but they disappear and, in a huge majority of cases, we never hear about them in the press or on TV or on social media.

They are society’s forgotten.

I wondered why this is. Why do some cases generate huge coverage, and others garner almost none? It made me want to write a story that featured a long-term missing person. Why did they disappear? Why did they attract no attention? Does someone not want them to be found, and why?

It was an intriguing premise for a book, and whilst writing my new thriller, The Devil You Know, I was catapulted back to a case that I was involved in way back in 2009.

I was the Duty Sergeant at Kentish Town, North London and had just come on duty after a few days off.

A 30-year-old Londoner called John Regan had vanished a week earlier after going out drinking on a Wednesday night.

He’d been out in Camden with friends when he’d been refused entry to a club, so decided to leave. But he didn’t return home, and when he didn’t turn up for work on Monday, he was reported missing. He’d been drinking and the last sighting of him was on CCTV in Camden Market, heading towards the canal towpath.

This was now serious. A high-risk missing person case. Despite extensive enquiries, no trace of the sports betting company analyst could be found.

His family had started a Facebook page and it garnered significant attention on social media, amplified by several celebrities including Dave Gorman, Claudia Winkleman and David Mitchell. Yet I’d heard nothing about John Regan on the radio or TV news, either locally or nationally, and it hadn’t made any of the newspapers I’d seen.

The canal had already been searched by divers. But – as Occam’s razor suggests – when faced with competing explanations, the simplest answer is likely to be the one that makes the least assumptions, so I sent officers back to have another look.

This was, after all, where Mr Regan had last been seen. And it is an unpleasant fact but a corpse in a body of water can resurface after a period of time. Sure enough, within an hour, two officers armed with decent torches had seen a shape just underneath the edge of a canal boat close to the lock.

I attended the scene, and there was a vague outline of a trainer, just visible. I called for assistance from the maritime support unit and we soon had a small boat on the scene, and the help of the experts in body recovery from water. Within a few minutes, the maritime team had managed to secure and bring a body to the surface.

Tragically it was Mr Regan – just a few metres or so from where he had last been seen a week earlier. His pockets were full of cash, he still wore an expensive wristwatch, so robbery could be excluded, and the fact his belt was unbuckled and his trousers were unbuttoned told the story of what had happened a week ago. No suspicious circumstances, just a tragic accident. A man caught short on his way home, falling into a dark, cold canal. A tragic accident.

Yet despite the fact the dissapearance was totally out of character and hugely concerning, it barely scraped into the public consciousness.

The family pushed hard, but still it barely made a dent in the wider public’s consciousness. Now, this was in 2010 and social media was still in its relative infancy, but things were about to change.

Fast-forward 13 years to January 27, 2023, and a woman called Nicola Bulley. The 45-year-old mortgage adviser went missing whilst walking her dog in St Michael’s on Wyre, Lancs. In essence, a similar situation.

We all now know the details of this terrible, tragic case, but at its heart what was most notable was the change in the media landscape – and how this case was perceived by the public at large.

Ms Bulley’s disappearance gripped the nation and not in a good way. Traditional media reported extensively, as one might expect, but that was not what shocked me. It was the so-called “citizen journalists”.

Suddenly, the nation was competing with itself to answer the question: “What has happened to Nicola?” Conspiracy theories surged, suspicion fell in all directions – risibly against the family of Nicola.

I remember reading a Facebook group commenting on a press conference. “I didn’t like the way her partner looked left and right when he was asked a question. I reckon he knows more than he’s letting on,” stated one armchair sleuth.

It also really made me consider what else could make Nicola stand out against the many individuals that do go missing, every day.

It’s a sad, but undeniable fact that a woman going missing will always attract more public attention than a man. This seems almost baked into society and will always galvanise the public’s attention and their thirst for information.

Nicola was an attractive, relatable woman, who had gone missing in the most perplexing of situations. This was pure fire for social media. There is another uncomfortable point that shouldn’t be ignored.

Nicola was a white woman. I’ve spoken to people who work for missing person charities and it is undeniable that the ethnicity of the missing person will play a part in how much media attention their case garners. Even my friends had strong opinions. “I reckon she’s been kidnapped,” opined one. When asked how she’d arrived at that conclusion, she wasn’t able to explain why. It was as if there was a type of collective insanity gripping usually level-headed people.

Social media groups also had the police investigation team in their sights and were full of criticism of their “incompetence” – based on what, I have no idea.

On another Facebook group, I read: “The police have done a disgusting job, they’ve missed key pieces of evidence, haven’t searched the river properly, it’s terrible.”

As I was connected to a member of that group, I asked how they’d come to this opinion. “It’s obvious, isn’t it. Everyone knows it,” I was told. I tried again: “Specifically, where did you hear the information that allowed you to come to that conclusion?”

Of course, it turned out to be a YouTube channel. Or a TikTok video. Or an Instagram reel. It didn’t really matter where, the fact was social media had been gripped by a frenzy of speculation, none of which was based on anything other than guesswork, ill-informed and malicious gossip and a sinister desire to somehow be part of a national story. Media frenzies are nothing new, but this was different, and it was deeply unpleasant.

Amateur detectives, with podcasts or other social media channels, were crowding the scenes, searching locations, or filming at the riverbank where Ms Bulley had last been seen, often livestreaming to their channels.

Speculation was rife and it was (to me at least) based on nothing but second, or third-hand poor quality, unverified tosh.

Mostly it was just for social media likes.

The police media strategy didn’t help and rightly received some criticism from the coroner, and later an independent inquiry, but I don’t think that was what drove this frenzy.

Senior Investigating Officers and Major Inquiry Teams are not there to provide a running commentary on live investigations.

Their job is to investigate and, beyond necessary press releases to ask for public assistance, there is no need for forensically detailed updates or a running commentary.

The priority was always to find Nicola. The public do not always have a right to know – and, ironically, she was just where the police had initially suspected: in the river where it appeared she had fallen.

The speculation and allegations had been, at best, highly distracting for the police and her family and, at worst, horribly intrusive and very upsetting.

So why have certain sections of the public been gripped by the need to feel at the centre of enquiries such as this?

True crime is now a huge industry, from expensive, important dramatisations on mainstream television, through to cheap-to-make documentaries on streaming channels. Some of the highest-charting podcasts and YouTube channels feature true crime and the public’s thirst for the dark side of human nature seems stronger than ever. Everyone now fancies themselves a detective, it seems.

And we expect instant gratification.

We’re all walking around with a super-computer in our pockets giving us access to the darkest side of humanity at the click of a button. We can’t wait for police briefings, we can’t wait for the news, we want to feel part of it and we can’t trust the police to tell us.

We want it all, and we want it now. We want to binge-watch real life. Leave the police to do their job. I know trust in the constabulary is at an all-time low, with some justification, but they’re still the best at what they do when it comes to major inquiries.

They don’t always get it right, but scrutiny is higher than ever and you definitely won’t help by jumping in with both feet.

In fact, the chances are you may make things worse. Scrub that. You will make things worse.

● The Devil You Know by Neil Lancaster (HarperCollins, £16.99) is published today. Visit expressbookshop.com or call Express Bookshop on 020 3176 3832. Free UK P&P on orders over £25. Visit the UK Missing Persons Unit via missingpersons.police.uk