I'm not at all a particular fan of the "true crime" genre -- I get bad vibes that I take seriously -- but the psychology of some criminals interests me.
Manson, for instance: I own Bugliosi's "Helter Skelter" and "Manson In His Own Words" and the cheesier "Taming the Beast." Manson is interesting to me for his mind control. He didn't actually DO anything. Yet his "philosophy" (and he had one) ultimately encouraged others to kill... because there was, according to him (and according to many at the time), no difference in the states between life and death...
Gary Gilmore -- I own Mailer's "The Executioner's Song" and the subsequent psychologically profound, extremely sad book by Gary's brother Mikal.
And I have Capote's "In Cold Blood." (Profound because of Capote's ability to make you feel the exact psychological environment of both the Clutter family AND the killers. Nancy's horse at the very end, after every horrible thing, made me cry.)
Plus a not-that-profound book I bought a few months ago about the Kitty Genovese murder on the anniversary of her death. (I did learn something factually -- that it was a random murder by a psychopath rather than a guy killing his girlfriend while neighbors looked on, as I'd always assumed from reading about the case in college.)
So that's the crime stuff I own. Jack the Ripper material, for instance, is both way too graphic and way too simple for me. (In my mind, it's a simple case of a guy hating women and taking it out in extreme fashion on the only readily available victims --- whores; I don't see anything interesting psychologically about that.) A paperback about Ted Bundy, I remember reading in the late '80s and just feeling creepy about --- a failed law student attacking sorority girls seemed kind of blatantly sexually simplistic: violence just for the sake of violence.
RE Lizzie Borden: 30 years ago in the mid-80s, I read the Evan Hunter (Ed McBain) novel, where the author posited that Lizzie had been having sex with the maid and got busted... leading to the ax murders of her father and step-mother. I remember liking the book as a read at the time, understanding that the "lesbian angle" was cheesy, and then not thinking anything more about the case as a whole.
A couple of weeks ago on the utterly cheesy show "Ghost Adventures," though, the host interviewed a psychic who had worked in the Lizzie Borden home in Massachusetts and who claimed to have been "attacked" by the ghost of Lizzie Borden's father since she was claiming that the father had sexually abused Lizzie Borden since she was a kid... I didn't particularly believe the claims of the featured psychic about being attacked by a ghost, but the mention of a theory of sexual abuse suddenly made sense: You don't SNAP like that without some deep underlying reason. I highly doubt that some STRANGER secretly burst into the Borden's (always locked) home and suddenly starting whacking away with an ax without either Lizzie or the maid Bridget (the only other people home at the time aside from the victims) being aware of it.
Maid Bridget went back to Ireland. Lizzie went off to live a rather grand lifestyle (with her dead father's money) in the better part of town, at one point living with an actress (Nance O'Neil), which caused her sister to move out and never speak to her again. (!) (Lizzie, by the way, asked to be, and was, buried next to her father.)
So, yeah, I just ordered $100 worth of Lizzie Borden books. :)