The self-proclaimed Zodiac Killer is directly linked to at least five murders in Northern California in 1968 and 1969, with two other victims surviving despite serious injuries. However, he might have been responsible for more killings. He taunted police and made threats through letters sent to area newspapers from 1969 to 1974, before abruptly ceasing communication. Through that correspondence, he claimed to have killed as many as 37 people. Despite intensive investigations—and multiple theories pertaining to the killer’s identity—no one was ever caught for the crimes, and the case remains open. The mystery surrounding the murders has been the subject of numerous books and movies, including director David Fincher’s acclaimed 2007 movie Zodiac.

On August 1, 1969, the San Francisco Examiner, San Francisco Chronicle, and Vallejo Times-Herald each received an identical handwritten letter in an envelope without a return address. Beginning, “Dear Editor: I am the killer of the 2 teenagers last Christmas at Lake Herman,” the letters contained details from the Zodiac Killer’s murders that only the perpetrator could have known. The killer went on to threaten further attacks if the letters weren’t printed on the front page of the papers.