What serial killers were inspired by others?

[Defective Detective]

Either in their MO or victim selection or other miscellany.

I can think of only two that are known with certainty - Dennis Raeder was inspired to write his taunting letters to the police by Zodiac (and on a more abstract level Jack The Ripper), and Ted Bundy claimed that the Ripper inspired him to try for a double event. It seems likely that the Texarkana Phantom influenced Zodiac's hood and signature at Lake Berryessa, but of course that remains conjecture.

Are there any others, known or speculated? Use any definition of 'inspired' you please; I'm not choosy.

[Mayerling]

Either in their MO or victim selection or other miscellany.

I can think of only two that are known with certainty - Dennis Raeder was inspired to write his taunting letters to the police by Zodiac (and on a more abstract level Jack The Ripper), and Ted Bundy claimed that the Ripper inspired him to try for a double event. It seems likely that the Texarkana Phantom influenced Zodiac's hood and signature at Lake Berryessa, but of course that remains conjecture.

Are there any others, known or speculated? Use any definition of 'inspired' you please; I'm not choosy.

Well, except for his modus operandi (poisoned capsules), and his extortionist threats to various people, Thomas Neill Cream certainly must have considered his actions to have the Ripper's actions as a model. Cream was in Joliet Prison in 1888, but word of the killings were a world wide news story. Previously he had committed crimes connected with abortion-murder or poisoning (including one poison victim who was a man, Daniel Stott), but there was a financial angle to most. Released in 1891, he comes to London with part of an inheritance, and starts killing prostitutes in Lambeth and Stepney, a bit higher (economically) than the victims in Whitechapel. He returns to Canada to get the rest of his inheritance, and when he returns to London in early April 1892 he reads or hears news items linking Frederick Deeming to the Ripper murders, in particular the "double header". Immediately he goes out and murders two prostitutes on one night, but again with poison. So there is a kind of copying (though part is through a misreading of newspaper gossip with fact via the career of Deeming).

Jeff