A serial murderer known as "the Zodiac" claimed responsibility for at least five murders in Northern California in the late 1960s,
and he may have committed more. Detectives, cryptographers, amateur sleuths,
and other inquisitive people spent more than 50 years trying to decipher the 340-character hidden message...
...that the Zodiac Killer gave to the San Francisco Chronicle in a card in November 1969.
Three researchers from three different continents reported that they had finally cracked the message after months of code-crunching during the pandemic.
The FBI's experts verified the answer, supporting the assertion further (and even tweeting about it).