A computer attempting to crack cryptic letters left by the Zodiac killer has a very disturbing side-effect.

The Zodiac killer was one of the most infamous criminals of the 20th century, leaving behind a string of unsolved murders that spanned from 1968 to the early 1970s in Northern California.

During his reign of terror, in which he is believed to have killed five people but claims to have murdered 37, he sent mysterious coded messages to the media detailing his crimes, reports News.com.au.

The Zodiac killer was never caught and, in 2004, was officially declared inactive. His identity remains a mystery.


Despite this, an artificial intelligence software has been working non-stop to try and crack the serial killer's letters in the hopes of revealing who it is.

The machine, known as CARAMEL, was programmed to think like the killer. But years of thinking like a murderer has produced some very creepy and unexpected results.

Along with code breaking, CARAMEL is capable of creating poetry. Members of the public can play along, too. All you have to do is offer CARAMEL a topic and wait for the results.

Police sketch of the man suspected of being the
Police sketch of the man suspected of being the "Zodiac killer". Photo / News.com.au

We gave it a try and the word "disturbing" would be an understatement.

First we asked the computer to come up with a poem on the topic of 'love':
"No longer contemplating suicide. To wait a moment on an old finale, Singing songs of love and kiss the bride, Sing a song about the sons of Sally."
This is one the computer wrote about 'humans'.
"Corrupted by potential predators, From the slightest form of human primal, Through a space between selective pressures, At the land of modern day survival."
It then composed a poem about 'kittens'. Surely there is no such thing as a scary poem about kittens, right?
Wrong, so very wrong.
"To push my fingers through her facial hair! I feel the pain of being bruised and itchy, Lying naked on a grizzly bear, Hanging from the arms of Mary kitty."

After all the recent warnings about the dangers of artificial intelligence, it is hard not to be slightly disturbed by a machine, which is programmed to think like a serial killer, taking up a hobby of writing creepy poetry.