I don't know why I took so long to watch this, but I can say for sure that this story was made to be adapted by David Fincher, fits perfectly with his film style and, obviously, he did a great job, the screenplay and direction are top-notch, the performances are phenomenal, as are the cast. The narrative flows so naturally that I didn't even notice the 157 minutes passing by. After I watched, I did a little research and find that the case is open until today, but all the evidence, unfortunately, can't prove anything concrete. It seems that we will never know who killed those people.