Investigators have since drawn connections between Allen's classroom activities and the Zodiac's infamous communications. One of the Zodiac's letters specifically quoted lyrics from "I've Got a Little List," and the serial killer was known for purposely misspelling common words.

People who knew Arthur Leigh Allen as children say he confessed, drugged them, and brought them to the sites of Zodiac killer murders

Netflix’s This is the Zodiac Speaking focuses on Arthur Leigh Allen, but eight other men have been accused of being the killer.

Netflix has released a new true crime documentary series called This is the Zodiac Speaking, and it's got people talking about the legendary case all over again

The key to the three-part docuseries is interviews with the Seawater siblings, who knew Allen years before the Zodiac's murders in Northern California.

To hear a man who authorities believe was a serial killer remembered by people who once felt tenderly towards him is as confounding as it is compelling