Codebreakers investigating the Zodiac Killer’s cryptic letters have finally solved one of the murderers most fiendishly well encrypted messages. However, the identity of the killer remains a mystery.

Investigators have finally decoded one of the infamous Zodiac Killer’s messages, 51 years after it was mailed to the offices of the San Francisco Chronicle. One of the researchers told the Chronicle of his team’s discovery on Friday, revealing that the letter read:

“I hope you are having lots of fun in trying to catch me. … I am not afraid of the gas chamber because it will send me to paradice [sic] all the sooner because I now have enough slaves to work for me.” The letter continues with the killer repeating the same sentiment, declaring that death by execution would only send him to “paradice” quicker.

Big news in the Zodiac world — the 340 cipher, mailed to us at the SF Chronicle in Nov 1969 has been SOLVED. “I am not afraid of the gas chamber,” the killer said. But frustratingly gave no name. Story to come #zodiac

The letter was known as the ‘340 Cipher,’ after the number of characters it contained, was cracked by three amateur researchers, who fed it through a code breaking computer program. According to the researcher, a web designer named David Oranchak, a similar code was used by the US military in the 1950s.

As well as notifying the Chronicle, Oranchak and his associates passed the decoded letter on to the FBI, which still treats the case as an “ongoing investigation.”

The Zodiac Killer, so-called because of his use of the symbol from his Zodiac watch on his correspondence, stalked California’s Bay Area during the late 1960s and early 1970s, leaving a trail of bodies in his wake. He was never identified, though evidence pins him to five murders and two non-fatal shootings, and the killer himself claimed in his letters to have murdered 37 victims.

Prior to the solving of the ‘340 Cipher,’ one of the killer’s other letters, known as the ‘408 Cipher’ was cracked by a schoolteacher and his wife in 1969. The letter said little beyond “I like killing people because it is so much fun,” and “when I die I will be reborn in paradice.”

Think your friends would be interested? Share this story!