I've had that same fixation as well. I mean I grew up with that and each one was kind or a flashpoint of whats out there. But I knew a fair amount about that first hand. You're certainly correct that there can be a lot of commonality in the profiles. Afairc you Read Hunting Humans as well. Great book. I actually spoke with Elliot Leyton and his Teaching Assistant online way back.
Read pretty much every book on Manson family, Jonestown. I have a strange predilection to reading about psycho killers.
This was an interesting read as well.
Ted Bundy: Conversations with a Killer by Stephen G. Michaud
Ted Bundy and the authors purposely engage in a game of theoretical constructs where questions are third person. "So if you were the killer and you did this how would you do it, where the body end up, etc. Its chilling and amazing stuff. Amazing in that the cat and mouse seemingly went on for so long and all parties participating. The authors quickly knew it was the only way they were going to get a lot of information out of Bundy. He's an atypical profile though.