Jack the Ripper was an unidentified serial killer active in the largely impoverished areas in and around the Whitechapel district of London in 1888. The killer was nicknamed "Jack the Ripper" due to the brutal nature of the murders, which were perpetrated on five prostitutes and became notorious for the mutilation of the victims' bodies. Some modern theories suggest the killer may have been a woman, perhaps a midwife or abortionist, known as "Jill the Ripper".