The identity of Jack the Ripper is believed to have been confirmed through DNA analysis of a shawl that was allegedly present at the scene of one of the notorious serial killer’s murders.
Jack the Ripper is one of history’s most notorious serial killers. An individual unidentified for a long time in history, his name has been linked to multiple (widely believed to be five) brutal murders of women in Whitechapel in the autumn of 1888.
Russell Edwards, after dedicating over two decades to studying the Jack the Ripper case, has become one of the most significant researchers on Jack the Ripper.
Several years after starting his research, Edwards was alerted in 2007 to a shawl being auctioned, which was believed to have belonged to one of Jack the Ripper’s victims, Catherine Eddowes.
Edwards took said shawl to Dr Jari Louhelainen, a Senior Lecturer in Molecular Biology at Liverpool John Moores University, for confirmation.
The Shawl
The shawl was reportedly in the possession of the family of a policeman stationed in the East End during the 1880s. In the 1880s, long before DNA testing, it was common to burn the belongings of victims. However, it is believed that the shawl was taken by a policeman on duty and then left unwashed for decades before being auctioned off to Russell Edwards.
Russell Edwards took the shawl to Louhelainen on multiple visits to Liverpool in 2014. Through initial photographic analysis to identify the stains on the shawl, Louhelainen confirmed the dark stains were ‘consistent with arterial blood spatter caused by slashing’. However, Louhelainen also discovered another stain — seminal fluid.
DNA Testing
Louhelainen compared mitochondrial DNA (mtDNA) samples to identify a match between the stains on the shawl and blood samples from living descendants of the victim Catherine Eddowes and a prime suspect, Aaron Kosminski.
mtDNA analysis is carried out by extracting a sample of DNA from both sources, reading their unique genetic code, like post codes, and comparing the two codes for a possible match.
While mitochondrial DNA is not unique to each individual like nuclear DNA, it can link individuals through maternal lineage, and mtDNA is also present in larger quantities per cell, making it more resilient to degradation over time.
Polymerase chain reaction (PCR) is commonly used in forensic science and was used by Louhelainen in his research. PCR is the multiplication of a targeted section of DNA, like picking up a plant from your garden and sprinkling it with magic dust to make it grow more quickly. Unlike the plant analogy, DNA that is left outside the body does not replicate and grow naturally.
PCR occurs in cycles of three steps: denaturation that separates DNA strands like gently pulling apart the plant’s roots, annealing where primers bind to target DNA like sprinkling magic dust on the seeds so they know where to grow, and extension where new strands are synthesized like watching the plant rapidly grow in seconds. Each PCR cycle doubles the amount of DNA.
This amplification allows for useful samples present in minimal amounts to be exponentially amplified and create sufficient material for analysis. This is why PCR is a crucial tool for forensic science.
One of the tests conducted to compare DNA from the bloodstains to blood samples of Karen Miller, a descendant of Miss Eddowes, provided a perfect match. Miller’s DNA also carried a rare genetic variation which only occurs in one in every 290,000 people. Edwards’ saw this as strong evidence suggesting the bloodstains’ connection to Miss Eddowes and the presence of the shawl at the crime scene. However, the mtDNA could still come from others with the same variation.
Next Edwards worked on getting in touch with a living descendant of Kosminski, whilst Dr. Jari extracted the mtDNA from the semen stain. Edwards eventually found a young woman, a descendant of Kosminski’s sister, who would share the same maternal mtDNA as Aaron Kosminski. The tests to compare the DNA from the semen stain to blood samples of the young woman also came back with a match.
So, who was Aaron Kosminski?
Kosminski has always been on the list of credible suspects. Even despite a good identification by a witness and an 1894 police report that reportedly identified Kosminski as the prime suspect, police at the time did not have enough evidence to convict Kosminski.
Kosminski was a Polish immigrant who worked as a barber. He was sent to an asylum in 1891 with a history of mental health issues and violent behaviors, where he remained until he died in 1919.
What’s Next?
Despite all the evidence, the research has not satisfied critics. The authors of the published study have omitted key genetic details, claiming that the Data Protection Act prevents them.
However, forensic scientist Walther Parson argues mtDNA sequences pose no risk to privacy and the omission of this detail undermines the credibility of the research: “… I wonder where science and research are going when we start to avoid showing results…“.
Hansi Weissensteiner, a researcher in bioinformatics with a focus on mtDNA analysis, also refutes the research based on limitations of mtDNA analysis, which he says can only reliably exclude suspects. Since mtDNA is passed down with minimal mutations, a large group of people can share the same mtDNA sequence. Critics also argue the shawl may have been contaminated over the years.
Following the recent discovery, Russell Edwards is calling for an inquest into the murder of Miss Eddowes. In an interview with the Daily Mail, Miller has backed the call to legally name Kosminski responsible for the murder of Miss Eddowes.
