After watching this film I was certainly intrigued but I thought that it was a rather slow film in many respects. However, when you think about it this film is really intriguing. One reason is that as a procedural the film utilizes this pacing to its advantage as it covers the events of the case.
Another reason is that Zodiac is based on the true events that took place in Northern California in the late 60s and early 70s. Furthermore, the culprit was never truly found even if there are a number of suspects who seem the most probable based on circumstantial evidence and testimony.
The point is we still don’t know who the Zodiac killer is even at the end of the film and this adds to the legend, mystery, and intrigue that surrounds the whole story.
Most definitely deserving of a movie adaption, director David Fincher, Jake Gyllenhaal, Robert Downey Jr., and Mark Ruffalo, make Zodiac work as a engaging albeit plodding procedural.