In the early hours of September 30, 1888, the body of Catherine Eddowes was found in a pool of blood on the smoggy streets of Mitre Square in London, joining a host of other women believed to be murdered and mutilated by the unidentified serial killer known as "Jack the Ripper".

New DNA evidence, obtained from a stained shawl supposedly found at the scene of the crime, has now weighed in on the mystery and points towards a man who has long been suspected of being Jack the Ripper: Aaron Kosminski. 

Reporting in the Journal of Forensic Sciences, scientists have carried the "most advanced" genetic analysis of the "only remaining physical evidence linked to these murders". Their findings suggest that Eddowes' killer might have been Kosminski, a Jewish Polish barber who was one of the main police suspects, thereby implying he may have been Jack the Ripper. 

The two researchers, led by Liverpool John Moores University in the UK, gathered genetic information from descendants of the victim and suspect, as well as the current owner of the item and any lab personnel who had worked on the silk shawl. They say they were then able to match the sequences of one of Kosminski’s relatives to mitochondrial DNA gathered from a semen stain on the material. The DNA evidence also suggests that the suspect had dark hair and dark eyes. This also matches up with the only eyewitness account of the crime and physical descriptions of Kosminski.

Kosminski was suspected of being the serial killer by a number of important members of the London Metropolitan Police at the time. Sir Robert Anderson, Assistant Commissioner throughout the murders, cited a “Polish Jew” as one of the most credible suspects, widely interpreted as being a reference to Kosminski.

In 1984, Assistant Commissioner Melville Macnaghten wrote about Kosminksi in the context of the Whitechapel Murders, saying: “He had a great hatred of women, especially of the prostitute class, and had strong homicidal tendencies; he was removed to a lunatic asylum about March 1889.”

So, is this case closed? Perhaps not.

The study does not go into the details of the specific genetic variants that link Kosminski to the DNA on the shawl, which is quite unusual for a scientific paper. It’s also worth noting that you can't uniquely identify a criminal using mitochondrial DNA. It’s typically only used by police to exclude people from a list of suspects. While this means that Kosminski can’t be excluded from the group of suspects, it is also not possible to exclude many people.

This is also not the first attempt to use DNA evidence to unravel the mystery of the Whitechapel Murders. American crime author Patricia Cornwell claimed that Walter Sickert, a well-known eccentric and painter, matched mitochondrial DNA profiles from letters written by Jack the Ripper. Another analysis by Professor Ian Findlay focused on a stamp on a letter, supposedly written by Jack the Ripper, and concluded that the murderer could have been female. It’s also been widely recognized that many of these letters are actually forgeries.

While this new study is arguably the “most advanced study to date regarding this case”, it’s worth remembering that it is just the latest in a long line of claims regarding the notorious killer’s identity.