This is based on the true story of a serial killer in the 1970’s in California who highlighted his murders with cryptic letters to newspapers. He killed at random, and called himself The Zodiac, and wrote his letters in a code. He also often sent bloodstained items of clothes along with these letters as a sort of proof. He was never caught. Robert Graysmith was working as a cartoonist at one of the newspapers where the letters arrived, and became caught up in the case. The film is based on his book of the events of the time.
The film itself is very well done. All the actors are great in their roles. I’m a big fan of Robert Downey Jr. and his portrayal of the drunken reporter is well worth watching. The whole atmosphere of the film is great. At times a little jokey, for example Toschi’s continual search for animal crackers, but it is also true to life, and when required it does become creepy and darker.
The problem with this film is that it is based on a true story, and I think it may stick to the truth a little too much, to the detriment of the flow of the film. There are constant jumps in time. Characters come and then leave. There is no real resolution. In part because the killer was never actually caught, the film points out the most likely suspect, but the case is still open today.
Overall I thought it was an extremely well made film. Atmospheric and tense, with great acting, but because of the real events it just didn’t have flow and pacing of a great film. Still, it is well worth a watch. I suppose in a way it isn’t really a murder mystery, but rather a look at how the case impacts on the lives of the characters. As such it works.