A two-and-a-half hour police procedural that emphasizes the frustration of following procedure, Zodiac is an anomaly in age when shows such as “Law & Order” wrap up the most Byzantine cases in 60 minutes flat. Based on a still-unsolved murder spree of the late 1960s and ’70s, the movie pays attention to the sort of things most crime dramas leave out, including the hard work that goes into false leads and the complications that come with coordinating police departments. The movie fascinates, but at its own, idiosyncratic pace. This is a low-key departure from stylist David Fincher (Seven), who directs a sprawling cast that includes Jake Gyllenhaal, Robert Downey Jr. and Mark Ruffalo.
