SAN MARCOS, Texas (KXAN) — Kim Rossmo, a research professor in the School of Criminal Justice at Texas State University, questions the investigation which concluded the identity of Jack the Ripper earlier this year.
On March 12, a paper titled “Forensic Investigation of a Shawl Linked to the ‘Jack the Ripper” Murders” (Jari Louhelainen Ph.D., David Miller Ph.D.) was published on the Journal of Forensic Sciences claiming that a DNA match was made between blood evidence found on one of the Ripper’s victims and a living descendant.
The paper names Aaron Kosminski who was a prime suspect in the 1890s.
Rossmo, a retired Canadian police detective inspector, is critical of the paper’s findings concluding that the research is a forensic failure. He notes that many of the mistakes made in systematic wrongful convictions, a major research project he recently completed, were also made in the Ripper identity research. His commentary is also published on the Journal of Forensic Sciences.
“The underlying errors in reasoning and logic here — tunnel vision, suspect-based focus, confirmation bias, uncritical acceptance of assumptions, unreported error rates, and probability mistakes — are the same ones commonly found in wrongful convictions and other criminal investigative failures,” Rossmo said.
Key problems Rossmo identifies in the DNA research include:
- The shawl with which DNA samples were collected from was no reference in any investigation report from the time of the murders.
- Stains on the shawl are claimed to be from the victim and killer, but neither claim is scientifically verified by researchers.
- Bodily fluid stains thought to be from the killer are found on the shawl but there is no evidence sexual activity ever occurred in any of the Ripper’s murders.
- Mitochondrial DNA (mtDNA) was used to identify Kosminski as the killer but this type of genetic marker is not a unique identifier. While mtDNA testing can eliminate suspects, it cannot implicate them.
- While London Metropolitan Police identified “Kosminski” (last name only) as a prime suspect, the researchers claim this is the same person as “Aaron Kozminski,” who was an inmate at Colney Hatch Asylum. The records on both men had different biographical information.
“Tunnel vision involves a narrow focus on a single theory, such as the exclusive targeting of Kosminski for the mitochondrial DNA test, and can lead to a premature shift from an evidence-based to a suspect-based investigation,” Rossmo said. “Confirmation bias, a type of selective thinking, then becomes a problem. Human inclination is to confirm our theories by seeking out supporting information, interpreting ambiguous information as backing our beliefs, and minimizing inconsistent information.”
Jack the Ripper is one of the most well-known serial killers, thought to be active between 1888 and 1891, with his attributed victims killed in the Whitechapel area in London. His identity has remained unknown since those years.