Jack the Ripper is perhaps the most iconic serial killer in history. Part of the mystique of this dark figure is the fact that he was never identified, leaving room for endless sleuthing and speculation. Every Ripper fan has their list of favorite suspects, usually filled with famous and powerful people of the time to add even more interest. My favorite, of course, is that he was a time-traveling friend of H. G. Wells.
Now a private researcher, Russell Edwards, claims that he has finally solved the case. First I will present his story without comment, and then we can take a skeptical look at it.
Edwards claims he acquired a blood-stained shawl in 2007 that is supposed to be from Catherine Eddowes, one of the five fairly accepted victims of the Ripper. The shawl was apparently recovered from the scene of Eddowes murder, and was covered in her blood. Acting Sergeant Amos Simpson took the shawl home as a gift for his wife. She was, apparently, not impressed and stored the shawl away without cleaning it.
The shawl remained in the possession of his family until they auctioned it off in 2007 and Edwards acquired it.
Edwards then solicited the help of Dr. Jari Louhelainen, a Finnish expert in historic DNA. Louhelainen found that the 126 year old shawl contained a great deal of blood, likely all from the victim. However, he also found a semen stain on the shawl. Genomic DNA is unlikely to have survived 126 years sufficiently intact for DNA matching. However, mitochondrial DNA is more hardy and likely did survive.
Sperm, however, contain few mitochondria (almost none). Fortunately, Louhelainen was able to isolate an epithelial cell from the region of the semen stain. Epithelial cells line many tissues, and so it is possible that the cell (which would contain mitochondrial DNA) was from the same source as the semen itself.
Louhelainen was able to extract and amplify the DNA, and then type it, finding that it belonged to . . .
Also See: How Jack the Ripper Worked (howstuffworks)