Zodiac killer case cipher cracked by codebreakers after 51 years

A team of amateur codebreakers claim to have cracked a cipher attributed to the notorious Zodiac Killer after 51 years.

The note was originally sent to The San Francisco Chronicle, People reports, by the killer who is confirmed to have taken the lives of at least five people in California in the 1960s and claims to have killed more than 30.

The Federal Bureau of Investigation's San Francisco Division confirmed the discovery of the new message in a statement released on Friday.

"The FBI is aware that a cipher attributed to the Zodiac Killer was recently solved by private citizens," the statement read. "The Zodiac Killer terrorized multiple communities across Northern California and even though decades have gone by, we continue to seek justice for the victims of these brutal crimes."

The agency said that the Zodiac Killer case remains an ongoing investigation.

Expert David Oranchak posted his findings on YouTube about the message which has been dubbed the "340 cipher" because of the number of characters it contains.

"I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME," it reads.

The note, which was sent to the Chronicle in 1969, continues: "THAT WASNT ME ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT 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 WHERE EVERYONE ELSE HAS NOTHING WHEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH."

"I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE [sic] DEATH," it reads.

In an interview with the Chronicle, Oranchak, a 46-year-old web designer, said that he has been working on the Zodiac Killer's codes since 2006.

However, he required the help of two other amateur detectives to crack the 340 cipher: Sam Blake, a mathematician, and Jarl Van Eykcke, a warehouse operator, the news outlet reported.

Oranchak said that the team of detectives knew that they were close to cracking the code when they unlocked the phrases "gas chamber" and "the TV show," which appeared to be a reference to Jim Dunbar's AM San Francisco show on KGO-TV.

During a 1969 broadcast, a person claiming to be the killer said: "I don't want to go to the gas chamber."

"I could not have done this without them," Oranchak said of his partners. "All of us in the crypto community on the Zodiac figured the cipher had another step beyond just figuring out what letters belonged to the symbols, and that's just what we found here."