The term "Jack the Ripper" was derived from a letter made by a somebody claiming to be the killer and widely circulated in the media. The "From Hell" letter arrived with half of a preserved human kidney, supposedly taken from one of the victims, according to George Lusk of the Whitechapel Vigilance Committee. The letter also included an offer to show any further organs that might be found. In addition to the letter, which is now in the British Museum, other evidence has emerged linking James Maybrick to the murders. He was an employee of John Thompson, who hired Jack as a laborer. Under questioning by police, Maybrick admitted to having an affair with Mrs. Thompson. When she learned of this affair, she allegedly shot herself in the heart with her husband's gun. At the time of the murder, James Maybrick was serving a five-year prison sentence for theft. However, there are theories that he was actually the killer, and was allowed out on bail while his wife was dying. There's also a theory that he killed her by mistake when he went looking for his lover's body. Maybrick was later tried and acquitted for the murder of his wife. But the incident still haunts him through all these years later and may be why he killed again later on.