- Question
- Who was Jack the Ripper?
- Position‹3 of 6›
- Aaron Kosminski
- Argument
DNA linked Kosminski to the Ripper's fourth victim
Mitochondrial DNA found on a shawl belonging to Cathering Eddowes was a match for Aaron Kosminski.
The argument
The Ripper case remained unsolved for over a century after the murders, but scientific and historical interest in Jack the Ripper did not disappear even after the Ripper and all others involved in the case had died. In 2019, a peer-reviewed study was published in the Journal of Forensic Sciences based on DNA analysis of samples taken from a shawl found near the body of Jack the Ripper's fourth canonical victim, Catherine Eddowes. The genetic analysis indicated a match between the mitochondrial DNA found on the shawl and the DNA of Ripper suspect Aaron Kosminski. This hard physical evidence indicates that Kosminski was Jack the Ripper.
Premises
Counter-arguments
Critics note serious problems with the DNA claim. The shawl's provenance is unverified — it has no documented chain of custody linking it to the crime scene, and it may have been handled by many people over more than 130 years, so any DNA on it could be contamination. Mitochondrial DNA is shared down maternal lines and is not individually identifying: a match indicates a maternal relative, not uniquely Kosminski, and the study did not report the statistical frequency of the haplotype, which forensic experts called a critical omission. The work was also authored by a Ripper enthusiast with a prior theory, and other forensic scientists have declined to accept it as conclusive. On this view the shawl evidence is too compromised to establish that Kosminski was Jack the Ripper.
Rejecting the premises
[Rejecting P1] The shawl has no verified chain of custody to the crime scene and was handled by many people over 130 years, so DNA on it could be contamination rather than the killer's. [Rejecting P2] Mitochondrial DNA is shared along maternal lines and is not individually identifying, and the study omitted the haplotype's frequency, so a 'match' points to a maternal relative, not uniquely to Kosminski. [Rejecting C] Because the physical evidence is compromised and the analysis is contested by other forensic scientists, it does not establish that Kosminski was Jack the Ripper.