Miller and study co-author Dr Jari Louhelainen, senior lecturer in molecular biology at Liverpool John Moores University, were also able to test mitochondrial DNA from a blood stain on the shawl, which was a match for the DNA of Karen Miller, a descendant of Eddowes.
However, many researchers dispute Miller and Louhelainen's physical evidence, claiming there is no proof the shawl was ever present at Jack the Rippers crime scene.
Historian Hallie Rubenhold, authour of the new book The Five: The Untold Lives of the Women Killed by Jack the Ripper, has been among the Ripper experts to criticise the conclusions. “[T]here is no historical evidence, no documentation that links this shawl at all to Kate Eddowes. This is history at its worst,” she wrote on Twitter in response to a headline that claimed the newly published research "proved" Jack the Ripper had been identified.
Hansi Weissensteiner, an expert in mitochondrial DNA at Innsbruck Medical University in Austria, also takes issue with the mitochondrial DNA analysis, which he says can only reliably show that people, or two DNA samples, are not related. “Based on mitochondrial DNA one can only exclude a suspect.” In other words, the mitochondrial DNA from the shawl could be from Kosminski, but it could probably also have come from thousands who lived in London at the time.
The new tests are not the first attempt to identify Jack the Ripper from DNA. Several years ago, US crime author Patricia Cornwell asked other scientists to analyse any DNA in samples taken from letters supposedly sent by the serial killer to police. Based on that DNA analysis and other clues Cornwell posited the killer was the painter Walter Sickert, though many experts believe those letters to be fake. Another genetic analysis of the letters claimed the murderer could have been a woman.