Scientists Are Getting Heated Over the DNA Study Identifying Jack the Ripper

Critics think the study shouldn't have made it past peer review.

Jack the Ripper illustration

Five women were brutally murdered within three months and their killer has never been found. The public, however, gave him the name Jack the Ripper. Since the gruesome events of 1888, great effort has been put into discovering his identity, and on March 12 a team of scientists claimed they have produced “the most advanced study to date regarding this case.” The problem is that other scientists don’t think this study should have even made it past peer review.

The focus of the case report published in the Journal of Forensic Sciences is a silk shawl linked to the victim Catherine Eddowes. Study authors Jari Louhelainen, Ph.D. and David Miller, Ph.D. write that, to the best of their knowledge, the shawl is the only piece of physical evidence known to be associated with these murders. On the shawl is genetic evidence of both Eddowes and her alleged attacker in the form of blood and semen stains.

“In the case presented here, all data collected support the hypothesis that the shawl containes biological matter from Catherine Eddowes and that the mtDNA sequences obtained from semen stains match the sequences of one of the main police suspects, Aaron Kosminski,” Louhelainen and Miller write, referring to mitochondrial (mt) DNA. Louhelainen is a senior lecturer in molecular biology at Liverpool John Moores University, and Miller is a reader at the University of Leeds School of Medicine,

Kosminski, a Polish barber, was a prime suspect at the time of the killings but apparently vanished before an arrest. This study compared fragments of mtDNA retrieved from the shawl to genetic samples from the living descendants of Eddowes and Kosminski. The authors say that the presence of mtDNA on the shawl matches that of the mtDNA found in the descendent’s samples.

jack the ripper
"Jack the Ripper" murder sites. 

But critics of the study say key details on the specific genetic variants identified and compared are not included in the paper, as Science reports. The authors say they didn’t include the genetic sequences because of the privacy requirements of the Data Protection Act but mitochondrial DNA — which DNA known to be inherited from the maternal side — isn’t typically considered a threat to privacy.

mtDNA doesn’t serve as a concrete reference point for men. On Twitter, University of Leicester geneticist Turi King, Ph.D. explained that although the genetic material of Eddowes’ living relatives could theoretically link them to the victim, the “suspect couldn’t have passed on his mitochondrial DNA, as he was a man.”

The case, argues King and others, is far from closed. While the study authors have confidence in the shawl’s validity and its stains, it is impossible to say now that the damage done to it is truly because of the crime. At the time of the murders, items like clothing weren’t taken into consideration, and the shawl has traveled through numerous hands before arriving in this study.

Louhelainen and Miller write that this is the “most systematic and most advanced genetic analysis to date regarding the Jack the Ripper murders,” and while it’s true that it’s unique compared to other efforts because it’s peer reviewed, it remains to be seen whether history will believe them.

Abstract:

A set of historic murders, known as the “Jack the Ripper murders,” started in London in August 1888. The killer’s identity has remained a mystery to date. Here, we describe the investigation of, to our knowledge, the only remaining physical evidence linked to these murders, recovered from one of the victims at the scene of the crime. We applied novel, minimally destructive techniques for sample recovery from forensically relevant stains on the evidence and separated single cells linked to the suspect, followed by phenotypic analysis. The mtDNA profiles of both the victim and the suspect matched the corresponding reference samples, fortifying the link of the evidence to the crime scene. Genomic DNA from single cells recovered from the evidence was amplified, and the phenotypic information acquired matched the only witness statement regarded as reliable. To our knowledge, this is the most advanced study to date regarding this case.