I like the story of John Gracey. For a few reasons. He had, of course had severe emotional truma from his father, and even within himself. He hated his own identity. Most likely seeing himself and what he was in all of his victems. He felt rejected, and like he was living a lie. And he was a very good artist. The story is intregueing, to me anyway. Because of the psycological aspect of it. The same with Ed Gein, psycological gold. It's like in the silence of the lambs, that one man said that it was amazing haveing Dr. Lecter there to study. I'll be a theripist or something someday.
The Night Stalker, Richard Ramirez is my personal favorite study. Possibly because he was a hometown boy (we're both native El Pasoans - I've even been to the apartments on Fruta Avenue to check out where he lived as a child), possibly because of his overt Satanism, or maybe just the simple fact that he's a dyed-in-the-wool AC/DC fan, Ramirez captures my attention. The crimes he allegedy commited are just beyond sick - not your average prostitute-strangler. As far as unsolved crimes go, I'm a big fan of the original Zodiac killer. I think it was his taunts to the media and that freaky-weird costume he dons that got me hooked on that case!
My favorite is an unknown, he/she hasn't been got by the cops yet. Not a lot is known about him/her, other than the body count it over 800 and he/she always marks the Vic's with a Triangle. Most of the time on the inside of the right leg or on the lower to mid back.