Very human serial-killer movie. She really isn't a monster. Jenkins wants the audience to sympathize with this woman, and it's not all Hitchcock/Silence of the Lambs, ooh, serial killers are evil but still somehow appealing because they're so clever and charming.

It's a fairly real-feeling story of someone going over the edge. (Charlize Theron absolutely deserved all the praise she got for this.)

I don't know if this kind of movie would have gotten made about a male serial killer.