ARGUMENT 1: JACK DID EXIST
If it seems blindingly obvious that there was a serial killer active in London's East End in 1888, that's because... there was. All the leading authorities of the time thought so, and almost every historian and "Ripperologist" thinks so today.
That's not to say the experts haven't passionately disagreed over the years - you just have to look at the endless list of suspects, which has included everyone from prominent doctors to celebrated painters to members of the royal family. But whoever he was, Jack DID exist.
That notorious nickname came from a letter which was sent to the police, beginning with the words "Dear Boss" and signed "Jack the Ripper". Was it a hoax? Perhaps. But the letter did mention that he would clip his next victim's ears off, and Catherine Eddowes would indeed be found with part of her ear severed.
Catherine was one of the canonical five victims which are attributed to Jack the Ripper. The phrase "canonical five" is used to distinguish them from a number of other women who were murdered in the area during the same general time period. This is an important point, because it confirms the similarities between the five crimes, and marks them out as the work of one person.
All five murders no doubt came from the same hand.
Police surgeon Thomas Bond put it very clearly, saying "all five murders no doubt were committed by the same hand". The crimes weren't identical - far from it. Mary Ann Nichols, the first of the canonical five, suffered slashes to her body, but wasn't mutilated beyond that. Mary Jane Kelly, the last of the five, was utterly eviscerated in the most gruesome way imaginable.
Does this mean they weren't killed by the same person? Not at all. It's a myth that serial murderers stick religiously to one MO. In many other cases, such as the similarly never-identified Zodiac Killer, you can see different techniques employed to satisfy blood lust. With Jack's victims, there seemed to be an escalation in violence as he became bolder and more maniacal.
The one exception was Elizabeth Stride, who strangely suffered no grisly mutilations beyond the killing cut to her neck. This might have been because the Ripper was interrupted, or because she was indeed killed by someone else. Even if she was, that leaves four women who were murdered by a man whose methods and intentions were clearly discernable, even if his identity was anything but.
ARGUMENT 2: JACK DID NOT EXIST
"Jack is supposed to be responsible for five victims, but there were other similar murders before and after the ones attributed to him, both in this country and abroad in America and Germany." So says Trevor Marriot, a retired detective who spent over a decade investigating the Ripper killings. As he puts it, "The reality is there was just a series of unsolved murders and they would have sunk into oblivion" if it wasn't for the drooling media attention of the era.
Let's emphasise one point: Whitechapel in 1888 was a crime-ridden warren of casual violence and vice in the most squalid and overcrowded surroundings you can imagine. In this underbelly of London, women had been victimised and killed well before 31 August, the date of the first "canonical" murder.
One of them was Martha Tabram, a prostitute who had been stabbed almost 40 times in an attack of bloody severity. So why is she not classified as one of Jack's "official" victims? Because she was stabbed rather than slashed, which seems rather dodgy grounds for allocating blame. After all, even supporters of the Jack hypothesis agree that the killer's apparent MO did change over time, so there's no real reason to officially discount Martha as his victim.
We owe Jack the Ripper to the pioneering editors and unscrupulous hacks of the Victorian press...
But then, the whole flimsy notion of the "canonical five" is down to one text, the so-called Macnaghten Memoranda, written by Victorian police officer Melville Macnaghten. It states that "the Whitechapel murderer had 5 victims -- & 5 victims only". This was just one man's subjective opinion, but has been taken as definitive proof that, of the MANY women murdered in Whitechapel in the 1880s, five should put in a special category of their own, as the victims of one mysterious, made-up murderer.
Today, even Ripperologists argue over who should or shouldn't be considered "canonical". Should Martha Tabram be added as a sixth victim? Should Elizabeth Stride be removed from the list because her killer's MO was so different from Jack's? There have even been doubts cast over Mary Jane Kelly, the most "iconic" of Jack's victims, who was found utterly dismembered in her own home.
Surely Kelly's murder was the Ripper's grisly masterpiece? Only if you discount the discrepancies - such as the fact it was indoors, and the fact that it was much, much more gruesome than anything anyone had seen before. Peter Turnbull, author of The Killer Who Never Was, says: "Of note here is the sustained attack to the face which indicates her killer was attacking her personally. No other victim sustained such concentrated facial damage."
It seems very likely that both Kelly and Stride weren't killed by the same person who killed the other three canonical victims. And there is absolutely no proof those three were killed by the same person either. There may well have been copycats at work, inspired by the details of previous murders published in the papers.
The East End was a virtual warzone. People were robbed, maimed and stabbed to death all the time. What's likely is that the general atmosphere of fear and dread, bred by the squalor of the slums and journalists desperate to sell newspapers, spurred onlookers to connect a series of disparate crimes and create a bogeyman called Jack the Ripper.
Dr Andrew Cook, author of Jack the Ripper, puts the blame squarely on the panic-mongering press: "We owe Jack the Ripper to the pioneering editors and unscrupulous hacks of the Victorian press, the great-grandfathers of tabloid journalism who understood that murder sells papers."