Like many, when I saw the news that Jack the Ripper had finally been identified, I thought, “Here we go again”. Who was the serial killer going to be this time? Gladstone? WG Grace? After all, the list of suspects contains the likes of Prince Albert Victor, the Duke of Clarence and even Lewis Carroll, so I was bracing myself for somebody really spectacularly silly; perhaps even Queen Victoria herself.

But as I read more about the story, it became apparent that this wasn’t some outlandish claim peddled by a money-grabbing junk historian.

In fact, it all seems very sensible. In 2007, a businessman called Russell Edwards bought a shawl that was said to belong to Catherine Eddowes, one of the Ripper’s victims. Mr Edwards took the shawl to Dr Jari Louhelainen, a senior lecturer in molecular biology at Liverpool John Moores, and a specialist in genetics and forensics.

Using a process called “vacuuming”, Dr Louhelainen was able to extract enough DNA from bloodstains on the shawl to match the DNA taken from one of Eddowes’s descendants. Even more excitingly, Dr Louhelainen was able to find some seminal fluid, from which he was also able to obtain some DNA.

That DNA is a 100 per cent match for a female descendant of the sister of one of the Ripper suspects — a Polish-born hairdresser called Aaron Kosminski, who suffered from paranoid schizophrenia and hallucinations, and was admitted to mental asylums from 1891 until he died in 1919.

If the science is correct, then the case is closed after nearly 125 years. And even though I am a historian who delights in debunking junk history, this time I’m convinced. But I’m also disappointed.

Unlike so many suspects, Kosminski is boringly plausible. The idea that the Ripper was a madman who was strongly suspected by the police — and even monitored by them — rings true, but dully true. Because although my head realises that Kosminski has to be the killer, my heart doesn’t want the case to end. Like others, I’ve been fascinated not only by the case itself, but also by the legion of obsessive people who call themselves “Ripperologists” – a faux-scientific label if there was one.

Be in no doubt that these people will keep the case alive. The notion that there is nothing left to solve, no more leads to follow up, no more evidence to dissect, will surely leave their lives empty and seemingly worthless. One can already see anguished signs of this denial on discussion forums, in which the Edwards-Louhelainen theory is peevishly dismissed.

Among those who will doubtless be rubbishing the idea of Kosminski as the serial killer will be the crime writer Patricia Cornwell, who is the queen of Ripperology. In 2002, Cornwell published a book in which she confidently asserted that the painter Walter Sickert was the Ripper. Much of Cornwell’s evidence was flimsy — not least her desperate claim that the poses of the women in some of the artist’s paintings are similar to those of the corpses of the Ripper’s victims.

Cornwell’s problem, which is shared by many of her fellow Ripperologists — and, to be honest, by myself — is that she wanted the murderer to be someone remarkable. The notion that such unsolved sensationalised murders were committed merely by an obscure maniac is simply not satisfying. Kosminski’s modest character does not have sufficient strength to carry the hugeness of the story and the culture of books, films, TV shows and tours that has been built around it.

This is similar to the disbelief shared by members of the Israeli intelligence service when they tracked down Adolf Eichmann to a ramshackle house on the outskirts of Buenos Aires. It seemed ludicrous, even insulting, that the murderer of six million of their fellow Jews could be living in near poverty. It would have been more appropriate if Eichmann had lived in a sinister castle in Bavaria.

The truth is that the answers to so many of these notorious cases are indeed boring and short. President Kennedy was shot by a lone misfit, and was not the victim of some multi-tentacled conspiracy. In all likelihood, Lord Lucan drowned himself.

Subconsciously, we treat these horrible, true crimes as extensions of the entertainment industry. While a work of fiction may have Jack the Ripper as a personage, in truth, we now know that the murderer was a mere person.

But even if the DNA evidence had shown that the Ripper was, say, a son of Queen Victoria, many would have dismissed it. Mysteries are fun. Solved mysteries are not. Had Kosminski been found guilty in 1888, then the case of “Jack the Ripper” would have been all but forgotten. There were plenty of other serial killers in the 19th century, but few today can name, say, the likes of Dr William Palmer who poisoned several of his victims, or Sarah Freeman, who killed at least nine, including her own brother.

However, we must learn to accept the science, and not let our imagination triumph over the facts. That is indeed a worthy and sensible observation, and one we should all heed; but it’s not one that I find very satisfying. If Dr Louhelainen’s methodology is found to be flawed, then I for one will be secretly delighted.

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