2. The number of victims

How many women did Jack kill? Depending on who you ask it could be anywhere between four and upwards of fifteen!

Serial killers often have a ‘signature’ to their murders; a methodology and ritual that forms a part of their warped fantasy of the event. That signature also helps law enforcement track which crimes might be theirs. Most books on the subject attribute five killings, known as the ‘Canonical Five’, to Jack. These are: Mary Ann Nichols, Annie Chapman, Elizabeth Stride, Catherine Eddowes and Mary Jane Kelly. I feel the names matter as we deal with the case as they were real people with hopes and dreams. The Ripper murders happened well before many of the key physical and psychological forensic tools we have today, however there does seem to have been a clear modus operandi: he engaged with them so as to get close, cut their throat and then mutilated the body. So while three of the canonical murders are clearly part of this pattern, two of them are a little different: Elizabeth Stride and Mary Kelly. Elizabeth Stride exhibited the same pattern of having her throat cut but not the bodily mutilation — was this because the killer was disturbed or that it was not the same hand that ended her life? Mary Kelly’s murder was by far the most vicious and exhibited almost total mutilation. Was this because it was the only one that didn't happen on the street and so the killer had more time?

Then there are other murders that various ripperologists attribute to Jack. Notable amongst these are Martha Tabram who was found murdered 24 days before the first of the Canonical Five — was this Jack’s first kill, hence the reason it was different from the others? What about the later murders of Rose Mylett or Alice McKenzie? Or the unidentified female torsos found dumped in and around the Thames both before and after the Canonical Five were found? Or indeed one or more brutal murders of women that happened later in the USA? Without even knowing who he killed, it’s hard to know what evidence to rule in or out.