The Hunt for the Zodiac Killer

A new hunt for the Zodiac Killer gains unprecedented access to files, unearthing a complicated cypher that may contain the killer's name, and links between the killer and an unsolved case. A prime suspect emerges.

Did the Zodiac Killer serve in the U.S. Armed Forces? The team's supercomputer identifies strange symbols in the killer's code that would have been known to only a few when it was written.

A mysterious new cipher is uncovered, while the team's supercomputer uncovers a strange lunar pattern linking the killings. A taunting riddle by the killer may lead to a body. A second prime suspect emerges.

The FBI releases secret files and a handwriting analyst connects the Zodiac's letters to a taunting letter mailed 3,000 miles away in Albany, NY. The code team has a massive breakthrough on the Z-340.

The Code Team announces extraordinary news: A team member has solved the Zodiac's infamous Z340 code, which has eluded codebreakers for 50 years.