These writings contained clues about his identity and mysterious cryptograms, leading to much speculation over who the ...

The killer sent taunting letters and cryptograms to police and newspapers that included astrological symbols. There are several theories about the killer's identity, but they've never been identified.

Image by Wolfman12405, licensed under CC BY-SA 4.0, via Wikimedia Commons.

One of the most infamous aspects of the Zodiac's sinister saga was the series of letters he sent to local newspapers, in which he claimed responsibility for his gruesome crimes and taunted authorities ...