“Junius” clearly hated my books. Over the years I’d become used to his scathing one-star reviews appearing on Amazon every time I had a new one published. The anonymous account had become my online nemesis.

Just hours after my most recent book, Murder at Home, was released, I noticed a cancerous review from him, warning prospective readers that it was “abysmal — avoid”.

True to form, Junius — a pseudonym he used on Amazon to review books — proceeded to describe the “low quality” and “poor research” of what I had written, which “would disgrace an undergraduate dissertation”. I had, apparently, “nothing original to say”.

As I silently cursed Junius, a wave of powerlessness engulfed me. From past experience I knew I was just going to have to accept that there was nothing I could do. Regardless of how much I complained, Junius’s review would stay on Amazon like a scar.

I accept that not everyone will like my work. I am a criminologist who has written about 20 academic and, more recently, true crime books about violence, murder and serial killings. You must get used to criticism. However, Junius seemed to take things too far. His attacks were ad hominem — they seemed aimed at my credibility as much as any factual errors I might have made.

His one-star review of my new book immediately made an impact on the average scores, influencing the measures used by Amazon to rank new books and threatening to reduce sales. It was also crushing. No matter how many books you’ve written, you tend to remember the bad reviews, not the favorable ones.

Sitting at my desk, I glanced down at the front cover of my new book. There was the publisher’s puff — “The UK’s leading criminologist”, a title I’ve never claimed. However, it was, in that moment, strangely energizing. OK, I thought, let’s see if I can solve the mystery, find out who this Junius really is and work out if he has an axe to grind — if he has skin in the game, rather than being a reader who just doesn’t like my work.

Regardless of how much I complained, Junius’s review would stay on Amazon like a scar.

Here’s what I did.

I searched through all his reviews and he seemed to have eclectic tastes: the Jacobite rebellion, psychopathy, London, local history and the highwayman Dick Turpin, as well as true crime books.

I surmised that he was a historian or at least had a degree in history. Handily, he signed off his reviews with the hint of an address — “London, Middlesex” — although there was no trace of his name.

I typed “author”, “Dick Turpin” and “Jacobite rebellion” into the bar of a search engine. Up popped several authors who had dabbled in these different areas. One caught my eye because he worked in Middlesex — the historic county that now forms part of West London: Jonathan Oates.

I clicked on his profile. Oates had published many books about serial murder — he even has his own Amazon author page. He often appears in the media discussing murder and works as an archivist at Ealing Libraries in West London.

I called Ealing Libraries and asked to speak to Dr Oates.

“Who shall I say is calling?” I was asked.

“Professor David Wilson.”

“He’s upstairs. I’ll just go and get him.”

I heard the receptionist’s footsteps pad away. A few seconds later Oates said, “Hello”, and I simply asked if he was the Dr Oates who wrote about Dick Turpin — which seemed to help him relax — and then, with nothing to lose, in my best Glaswegian archly demanded, “And are you also the historian who reviews on Amazon using the pseudonym Junius and gives my books one star?”

There was silence at the other end. I felt like an idiot. I was just about to explain when Oates himself replied, “I’m so sorry. I apologize — I know. I’m so, so sorry.”

The phone went dead, but I knew I’d got my man. I cannot find the words to describe how delicious this moment was, but I can say that it ranks with some of the successful conclusions of live investigations I’ve been associated with.

I also knew I had to phone back. Oates (aka Junius) didn’t just have skin in the game, but head, hands, arms, legs and feet — he was a rival author covering many of the subjects I wrote about. This was no disinterested, impartial disgruntled reader; this was someone who considered himself a competitor.

This time, on the phone, Oates and I discussed how, if I had made factual errors, he could have emailed me at my university: I would gladly have corrected them and acknowledged his help. We talked about how it was clearly unethical to review the work of another author on the same topic using a pseudonym; I suggested that his attacks seemed personal rather than professional and that, as a trained historian — he has a PhD from Reading University — he should know better.

The phone went dead, but I knew I’d got my man.

To be fair to Oates, he took all of this on the chin and said that if he couldn’t take it down from the site he’d alter his review to something more balanced and critical rather than personal.

Later another thought struck me — had Oates perhaps reviewed his own books as Junius? Of course he had. He had given The Second Battle of Preston, 1715 five stars and described it as “detailed and comprehensive”.

This little saga is a warning to all those other trolling keyboard warriors: one day they will be unmasked. I know I’m not the only writer who has had this problem. But it is also a plea to Amazon to do more to stop so-called reviewers who use a pseudonym as a cheap way to denigrate a rival author.

Junius posted another review. Three stars this time, in which he describes Murder at Home as “novel”, with “interesting insights”, adding that “even old hands will find it of use”. Presumably that includes Oates.

David Wilson is a professor emeritus of criminology at Birmingham City University. His latest book, Murder at Home: How Our Safest Space Is Where We’re Most in Danger, is out now from Sphere