By testing stains found on a shawl allegedly discovered at Catherine Eddowes' 1888 murder scene, independent scholars Russell Edwards and Jari Louhelainen have determined that Jack the Ripper’s mitochondrial DNA matches that of a descendent of Matilda Kosminski. (They also traced mitochondrial DNA found on the bloody shawl to one of Eddowes’ descendants.) Matilda’s brother, Aaron Kosminski, had been suspected at the time of being Jack the Ripper; the mitochondrial DNA match, if it holds up under scrutiny, will probably exclude all other suspects and prove, by any reasonable evidentiary standard, that Kosminski was in fact the killer.
Kosminski was already a decent candidate; an eyewitness (who later recanted) claimed to have seen him near the scene of one of the murders, and his permanent institutionalization in 1891 would go a long way towards explaining why Jack the Ripper didn’t take more victims than he did. But circumstantial evidence seemed to point much more strongly to several other candidates—candidates who are now likely to be exonerated.
That said, the two researchers working on the analysis announced their findings as an exclusive to British tabloid The Daily Mail (which is not noted for its accuracy), and they’re promoting a book on the tests that will be published next week. While I doubt any of us at Mysterious Universe belong to the “only professional scientists can do science” school of thought, the fact remains that very few people have had a good look at what Edwards and Louhelainen have done. Until they have, we’re left in the not-particularly-enviable position of asking if two total strangers writing for a British tabloid would lie to us. If the answer to that question is no, it’s not a particularly confident no. I’ll feel better about the findings after they’ve been independently verified.