I found this film to be completely amazing, and the performances of Theron and Christina Ricci, who plays Selby, Lee's lesbian lover, to be completely believable and riveting. Since the story is based on actual events, I don't know how much of what the film depicts actually happened (one of the film's effects on me is to want to know what happened in the real story), but going just with the events as told in the story, it's amazing how they take you through Lee's journey.  She's never really a completely sympathetic character, but you almost understand how she gets to where she goes, from her first killing, which is fairly understandable, to her later killings which are harder and harder to justify.  But you see the progression that she makes - so unlike someone like Ted Bundy, they're not just cases of random murders.  Almost all of what she does is motivated by love, and the development of the relationship between Lee and Selby is riveting to watch.

Changing physical appearances is something that tends to draw a lot of attention in and of itself, but such a trick doesn't always bear out in the performance.  In this case, though, Theron's transformation isn't just in her physical appearance, but also in her speech and her mannerisms.  For me, it was a little distracting because her voice hasn't changed, and I happen to recognize her voice, so it was a bit incongruous hearing a voice I know coming from a person I didn't, but having seen some of her other work and having seen and heard some of her personal interviews, it really is amazing to see the job she does in this film.  After I saw the film, I heard that she had won a Golden Globe for her performance, and I was happy, even though I don't put much weight on the Globes.  I do hope that she at least gets an Academy Award nomination for this role, if not the statuette itself.

Christina Ricci also does a terrific job in this film as the deceptively mousy Selby.  Her short haircut and pretty face add to her innocent demeanor, but during the course of the film, you see how manipulative she actually is.

This film is definitely not for the faint-hearted as some of the scenes are fairly graphic, but it gets a strong recommend from me.