This blog http://vincentaliasjack.com/wordpress/matches/ posits that Vincent Van Gogh was Jack due to similarities in Vincent's handwriting and some of the Ripper letters. The blog also states that the killings occurred around the time of Vincent's mother's birthday. As has been stated many times, and I supposed must be said many more, you can prove anyone wrote any of the letters--nothing proves that the killer and the letter-writer were the same person! Anyway, we have Van Gogh now. Any Victorian celebrity left to accuse?