The Zodiac Killer is the pseudonym of an unidentified serial killer who murdered five known victims in the San Francisco Bay Area between December and October The case has been described as "arguably the most famous unsolved murder case in American history," and has become both a fixture of popular culture and a focus for efforts by amateur detectives.
He attacked three young couples and a lone male cab driver. Two of these victims survived. The Zodiac coined his name in a series of taunting messages that he mailed to regional newspapers, in which he threatened killing sprees and bombings if they were not printed. He also said that he was collecting his victims as slaves for the afterlife.
He included four cryptograms or ciphers in his correspondence. Two were solved in and , and two remain unsolved. In , the Zodiac claimed 37 victims in his last confirmed letter. Despite many theories about the Zodiac's identity, the only suspect authorities ever named was Arthur Leigh Allen , a former elementary school teacher and convicted sex offender who died in The unusual nature of the case led to international interest that has been sustained throughout the years.
The San Francisco Police Department marked the case "inactive" in but re-opened it prior to Investigators agree on four confirmed attacks by the Zodiac Killer in California.
Five victims were killed during these attacks, and two survived: [ 2 ]. From to , the Zodiac mailed heavily misspelled letters and ciphers to law enforcement and media outlets. Some letters began, "This is the Zodiac speaking" and were signed with a symbol resembling the crosshairs of a gunsight :. Two have been solved, in and The Zodiac's confirmed correspondence with date, recipient, and incipit :.
