It wasn’t a bad film, but it came across as a twisted romance. What fell short was portraying just how unstable she truly was. It would have been better to focus less on the romantic aspect and more on her mental state. She was completely off her rocker! All those intense interviews and the things that happened in court—those are missing. The movie seemed to almost want you to sympathize with her, but it didn't really illustrate how disturbed she was.

Source on TMDB