The Zodiac Killer is known to have murdered at ... Other attempts – notably by the American Cryptogram Association, Chronicle cartoonist Robert Graysmith, and author Gareth Penn (pen name ...

"I like killing people because it is so much fun." These chilling words were part of a cryptic letter sent to newspapers in ...

His letters to local news outlets featured cryptograms, in which he called himself “Zodiac.” They were also signed with a cross over a circle. He stopped writing the letters in the 1970s.

After 12 months of escalating violence, the Zodiac Killer seemingly ceased killing. For more than a year after his last attack, he continued to write letters and mail in cryptograms taunting police.