It seems almost unplausible to believe Naruto WON'T save Sakura. One, Naruto is on his way to the battle at this exact time, which seems too perfect. Two, Naruto just had a chat with the fox about getting rid of evil. Three, one of the first time Naruto changed someones heart was in the tournament vs Neji. Four, Sakura mentions there is "someone else". Five, the doctor who is killed mention asks whether the murderer is still in pain. Sakura asks the same of the guy who writes the love letter. Six, the guy is obviously suspicious and he MUST know something. Seven, Neji mentions how he has seen someone looking around for Sakura. The creepy guy has seen how Neji has noticed him over and over. Neji then says "its me". Eight, directly after this Sakura says, "oh its you", which is odd when seen directly after Neji saying "its me". Nine, Neji was treated by Sakura in tent 3 and would have known where to look for her. Ten, Neji asks where Sakura Haruno is instead of saying something like Sakura-chan, which is more appropriate considering they are friends. Eleven, Sakura and Neji are completely alone when he is examined and the docor who was killed recognized the killer as someone who was hurt. He couldn't have known Neji was hurt. Twelve, I find it hard to believe Kiba wouldn't have recognized something was odd about Neji. Thirteen, Sensors would have likely detected something wrong with Neji. Fourteen, if the doctor wouldn't have recognized Neji as a patient, having not have treated him, it couldn't have been Neji that killed the doctor. Guy in shadows watches Neji constantly. Why did the guy in the shadows stop watching Neji? I think he switched places with him before the other guys were killed because Neji seems "safe" to everyone after his speech. Fifteen, Neji was vulnerable so it would have been possible. Sixteen, the doctor before being killed mentions tents five and three. Seventeen, the creepy guy happens to be standing at the fifth one, before seeing Sakura in the third, which is odd. Eighteen, the guys bandages on his face remind me of Madara for some reason. Nineteen, Neji mentions to the guys "he slipped out of sight"? Seriously? Think about that for a second. Twenty, Neji doesn't use his eyes at all after the beginning. Isn't it odd that he doesn't use them when he should be on the look-out? Finally, my opinion on everything is that Neji was feeling weird and Kiba sent him away. Neji showed up to get treated and Sakura greeted him. Creepy guy noticed it and started watching Neji after he kills the doctors. Neji talks to eveyone and creepy guy decides to switch places or begin controlling Neji. He goes, as Neji to find Sakura and kill more doctors. He finds Sakura himself. Brings Neji there to kill, setting up a win-win situation. Neji kills Sakura or Sakura begins trusting him more after helping her defeat Neji. Creepy guy is Madara who would be able to not only control Neji, but get into the base un-noticed with his teleportation. Naruto comes in, senses Madara, and brings him out. He frees Neji from his cage, which is Madara's jutsu.(tournament reference) with words. Naruto saves the day, yet again. So neither Sakura or Neji will be killed.
Does this remind anyone of Bleach? It has a Aizen murder mystery feel.