"That's right, it's a rarity in the horror field but it does exist, and it is a force to be reckoned with. Because true trilogies are all about going back to the beginning and discovering something that wasn't true from the get go. Godfather, Jedi, all revealed something that we thought was true that wasn't true."
First one a simple case if you are expecting an sociopath or psycho crime. E2 is about team work and trust. The story per se is just a regular one compared to sociopath series norm. E3 things go wield for the existing case interrogation. The psychopath actual is regular one and murdered. Vicap now lost threads.