Jack the Ripper’s killing spree in the autumn of 1888 remains as one of the world’s greatest unsolved mysteries. However, the mystery can finally be put to rest, or at least that’s the case according to a self-proclaimed “armchair detective” and molecular biologist by the name of Dr. Jari Louhelainen.

According to Louhelainen, who works out of Liverpool John Moores University, the infamous killer that prowled the London streets and slain five prostitutes over a century ago is none other than a Jewish Polish immigrant by the name of Aaron Kosminski. So how did Louhelainen come to his conclusion? He used a “vacuuming” technique to extract DNA remnants from a shawl belonging to 2nd Ripper victim Catherine Eddowes. The shawl was acquired at an auction by businessman Russell Edwards in 2007. Edwards later reached out to Louhelainen in the hopes that the shawl may yield evidence that could finally put the case to rest.

Infrared imaging revealed blood patterns consistent with blood splattering from a slashed throat. DNA also confirmed that the blood was Eddowes’. Subsequent testing on the shawl revealed the presence of epithelium cells, which were tested and compared with mitochondrial DNA from a descendent of Kosminski’s sister. The results turned up a 99.2% match. Louhelainen is positive through the findings that Aaron Kosminski and Jack the Ripper is one and the same person. The results and findings were later published in a book by Edwards titled, Naming Jack the Ripper.

Scientists and Jack the Ripper historians, however, are more skeptical and are pointing out holes in Louhelainen’s revelation. For one, they pointed out that a positive identification through DNA is not possible since the shawl has been contaminated over the years by various handlers before, during, and after Eddowes’ murder. Others have also pointed out that even if the DNA does belong to Kosminksi, he could simply have been one of Eddowe’s many clients. Kosminski, after all, was known to have frequented east London where the murders took place.

Richard Cobb, who heads many Ripper conventions and expos, is also skeptical and pointed out that further analysis of the shawl will likely reveal the DNA of at least 150 other men who handled the shawl.

Sir Alec Jeffreys, the founder of the DNA fingerprinting technique, also weighed in on the matter and believes that Louhelainen’s findings need to be subjected to further peer review study before a more solid conclusion could be formed. He did note, though, that Kosminski is among the top list of suspects among many Ripper enthusiasts.

While Kosminski will probably never be fully proven as the perpetrator, he will likely never be fully vindicated either. He immigrated to London in 1881 and was just 23 at the time of the murders. He was also under suspicion by local authorities though there wasn’t sufficient evidence to charge him. Kosminski was later confined to a mental hospital where he died from a gangrene infection in 1919.

The Jack the Ripper case is one of those mysteries where we’ll probably never know the truth. But with today’s access to genetic testing, it seems as though it’s used more and more because of its ability to unlock vast amounts of data. Louhelainen’s findings do revive interest in the case, but ultimately only leads to more questions than answers.