The Zodiac Killer

The Zodiac Killer terrorized Northern California with at least five murders between 1968 and 1969, sending taunting letters and cryptograms that remain partially unsolved. A 2020 breakthrough cracked the 340 cipher, revealing a chilling message, but the Z13 cipher, which the killer claimed contains his name, still stumps investigators. The case has generated more amateur investigation than any crime in U.S. history, surpassing #3 (MH370) in public engagement. Over 50 years later, the 408 cipher was solved in 1969, yet the killer's identity eludes authorities. This case holds the record for the most amateur sleuths involved, with over 5,000 tips annually. The San Francisco Police Department spent decades on it, but no conclusive DNA or fingerprint matches have been made.