It surely won't be the last theory offered, but a century and a quarter after the notorious crimes of Jack the Ripper, an "armchair detective" has employed DNA analysis on the blood-soaked shawl of one of the Ripper's victims, and has declared it in a new book an unambiguous match with Jewish immigrant Aaron Kosminski, long considered a suspect. Kosminski died in 1919 in an insane asylum. The landmark discovery was made after businessman Russell Edwards, 48, bought the shawl at auction and enlisted the help of Dr Jari Louhelainen, a world-renowned expert in analysing genetic evidence from historical crime scenes. Using cutting-edge techniques, Dr Louhelainen was able to extract 126-year-old DNA from the material and compare it to DNA from descendants of [Ripper victim Catherine] Eddowes and the suspect, with both proving a perfect match. (Also at The Independent.) It's not the first time DNA evidence has been used to try to pin down the identity of Jack the Ripper, but the claimed results in this case are far less ambiguous than another purported mitochondrial DNA connection promoted by crime novelist Patricia Cornwell in favor of artist Walter Sickert as the killer in a 2002 book. Update: 09/07 16:03 GMT by T : Corrected Sickert's first name, originally misstated as "William."