Nicomorphinist
Bluelighter
There was a good show called "American Ripper" that was on for a while about a year ago where H.H. Holmes like great great grandson is going around doing research to try to prove that Holmes and The Ripper were the same person. I keep meaning to look up whether or not the show is coming back on the air, but I'm doubting it will because I don't see it as likely that they will be able to prove one way or another that they are or aren't the same person and then that basically seems like it would end the show in an anticlimactically.
There did seem to be some clues that they might be the same person, particularly the fact that records indicate that Holmes was in London giving lectures on how to dissect corpses as the same times as some of the ripper murders, and the fact that he was a doctor and that it has often been thought that the ripper might have been to have been able to dissect his victims so easily.
However, I don't see how Holmes is anything like Manson in terms of ideology. He didn't want a race war and didn't seem to have any political motivation for his crimes, so I'm not sure where you got that idea.
That actually was a typographical error -- I can actually see no reason why Manson and Holmes are included in the same group in any respect other than he killed people, and though the Manson people killed on more than one occasion, Manson was really not a serial killer.