Jack the Ripper

Jack the Ripper, also known as Jolly Jack (TV: The Talons of Weng-Chiang, PROSE: Matrix), Saucy Jack (COMIC: Ripper's Curse), and Leather Apron (PROSE: Matrix) was the name given to a serial killer who brutally murdered prostitutes from London's East End in 1888. Most people agreed that only five murders were canon. (PROSE: Matrix, COMIC: Ripper's Curse)

Potential Suspects
In post-Time War history the Re'nar war criminal Mac'atyde could be directly connected to the last three murders which he intended to blame on the Ju'wes. His pursuer, "Sir Charles Warren", couldn't stop him until the fifth victim was killed because he already knew what Earth history said about the murders.(COMIC: Ripper's Curse)

The Valeyard used the murders to power the Dark Matrix. He created an alternate timeline where the murders continued leading to anarchy in London. Eventually, he killed through his undead wraiths and followers, the Jacksprites. (PROSE: Matrix) The Fellowship committed murders, usually women, to summon the Yssgaroth into the universe. William Blake and the Seventh Doctor saw the group's albino leader at a bordello around the time of the murder of Elizabeth Stride, the third victim. All known members were caught in a fire. (PROSE: The Pit)

Jack the Ripper was believed caught by the Silurian Madame Vastra, who proceeded to devour him. She found him "stringy, but tasty all the same". (TV: A Good Man Goes to War)

Other References

 * The killings of Li H'sen Chang were blamed on Jack the Ripper by some newspapers. (TV: The Talons of Weng-Chiang)
 * The Fifth Doctor planned to investigate the mystery of Jack the Ripper's identity for the use in his book Doctor Who Discovers Historical Mysteries. (AUDIO: The Kingmaker) By his Eighth regeneration, he believed he knew Jack the Ripper's identity. (PROSE: The Bodysnatchers, Interference - Book Two)
 * Chris Cwej believed he knew Jack the Ripper's identity too. (PROSE: Dead Romance)