The Zodiac letters

The Zodiac letters are a series of four encrypted messages believed to have been written by the famous Zodiac Killer, a serial killer who terrorized residents of the San Francisco Bay Area in the late 1960s and early 1970s. The letters were likely written as a way to taunt journalists and police, and though one of the messages has been deciphered, the

three others remain uncracked.

The identity of the Zodiac Killer also remains a mystery, though no Zodiac murders have been identified since 1970.