It is not known for certain how many victims Jack the Ripper actually had, although there is a general consensus that there were 5 victims.
The problem with regards the exact number is that the generic police file that cover the Jack the Ripper murders, the Whitechapel Murders file, actually has eleven names on it.
Some of these may have been victims of the ripper other most certainly were not.
Emma Elizabeth Smith, who was attacked in early April 1888, and who was the first lady whose name appeared on the Whitechapel Murders file, was almost certainly the victim of a local gang and therefore not a victim of the killer whom we now know as Jack the Ripper.
In early August 1888 Martha Turner was found murdered on a first floor landing of George Yard Buildings. There is still a considerable amount of debate as to whether or not she was a ripper victim.
Those who say that she wasn’t argue that her injuries were different to those suffered by the five acknowledged victims. Indeed, the nature of her injuries were more of a frenzied knife attack as opposed to the more calculated mutilations inflicted on the bodies of the five later victims.
Those who believe that Martha may well have been Jack the Ripper’s first actual victim argue that her killer most certainly targeted her throat and abdomen, just as the ripper did with his later victims, and that a this may have been a learning curve for the murderer in that, whoever was responsible, would have been left covered in blood. This may have led him to have developed the modus operandi that became his hallmark by which he asphyxiated his victims before commencing the mutilations, a method that would have resulted in minimal blood spattering.
The five definite ripper murders began on 31st August 1888 with the murder of Mary Nichols in Buck’s Row, Whitechapel.
This crime was followed a week later by the murder of Annie Chapman on 8th September in Hanbury Street.
On the 30th September 1888, and after an absence of several week, the killer struck twice in less than an hour, killing Elizabeth Stride in Berner Street and Catherine Eddowes in Mitre Square.
The, on 9th November 1888, the body of Mary Kelly was found in her room at 13 Miller’s Court off Dorset Street.
There were later murders that may have been the ripper’s work, but many of the police at the time, and many experts today, believed and believe that Mary Kelly was the last of Jack the Ripper’s victims.