Jake Gyllenhaal, Mark Ruffalo and Robert Downey Jr. have all signed on to the project. According to Variety, Gyllenhaal will play Graysmith, a San Francisco Chronicle editorial cartoonist who gathered facts about the Zodiac killer. Ruffalo will play the lead police investigator and Downey will play a reporter.
The Zodiac murders were marked by a series of taunting messages and codes sent to San Francisco police and newspapers. The author of the letters -- a person thought to be the killer -- referred to himself as "The Zodiac." Decades later, the killer remains at large.
Production on the Zodiac film is scheduled to begin in August. -- Mac Slocum