<p>Jack the Ripper's DNA could match that of respected British artist Walter Sickert, according to a new book from U.S. crime novelist Patricia Cornwell.</p>
<p>In "Portrait of a Killer: Jack the Ripper -- Case Closed," excerpted in the December issue of Vanity Fair, Cornwell describes how she and a team of investigators came to their conclusion after analyzing DNA samples from 55 letters, envelopes and stamps sent by Jack the Ripper; Sickert, as well as his wife and his mentor, and Ripper suspect Montague John Druitt.</p>