Just what is it about psycho killers that people find fascinating? I don't know, but Harold Schechter's Psycho USA: Famous American Killers You Never Heard Of is a great collection of obscure American killers. There are serial killers, mass murderers, Bluebeards, poisoners, and robbers and kidnappers who just sort of snapped and started carving people up. This is some gruesome stuff. It's the sort of thing that should appeal to fans of true crime and the more gruesome sorts of horror.
The only complaint I have is that not all of the killers seem like psychos. Ada Lebouf had a reasonable case for self defense, and even she was guilty, the case seemed more like a standard love triangle than a psycho killing. The rest, though all seem like total nutjobs.
This is a cool book.