The myth is based on the unidentified serial killer of the same name, that originated from London's Whitechapel district. The serial killer, supposedly murdered prostitutes, raped them, and took out their internal organs. The case was widely investigated but remained as an unsolved mystery. The myth is said to have existed in GTA IV.
Players have reported having seen the killer, assaulting prostitutes at dark hours, similar to real life. However, no evidence is present to support these claims and theories about Jack the Ripper are usually considered false. The mission Portrait of a Killer could be considered an Easter egg, as it shares the name of a real life book, written by Patricia Cornwell about Jack the Ripper.