After the first test failed to find DNA on the unsealed letter, Cornwell commissioned more sophisticated and time-consuming mitochondrial DNA tests. The new results, which came back two weeks ago, found DNA from a single person on the suspected Ripper letter. The tests also found DNA on the Sickert letters, but the DNA was a blend of many different people. There was a match between the DNA on the Ripper letter and the blended DNA on the Sickert letters. Cornwell's DNA expert points out that this is likely a coincidence, the mish-mash of blended DNA matching a sequence from the DNA on the Ripper letter. But Cornwell herself believes it is "a cautious indicator that the Sickert and Ripper mitochondrial DNA ... may have come from the same person."
After Primetime first reported Cornwell's theories in December, a woman in Britain contacted the author and told her she had a century-old hotel registry book with an entry signed "Jack the Ripper." Cornwell flew to England to see the book, and found that it was filled with crude annotations and obscene sketches that she believes are consistent with Sickert's work and personality. She turned the book over to the Tate Gallery, home to many of Sickert's paintings, for examination.
Primetime asked established Ripper experts what they thought of Cornwell's theories. Some said they thought they were feasible, while others dismissed them as "rubbish."
But Cornwell has not been deterred. She is planning to continue hunting for physical proof of the Ripper's identity — not for his sake, but for his victims' sake.
Recalling the unvisited, untended graves of the five young prostitutes, Cornwell said: "They have a right to have justice after 113 years. They have a right for someone to care about them for once and not to care about him. ... He doesn't deserve to be mythologized and turned into some hero played by movie stars. And he doesn't deserve to have his art celebrated."
This story originally aired on Primetime Dec. 6, 2001.