Subtitles section Play video Print subtitles December 20, 1968. Two high school students named Betty Lou Jensen and David Faraday are making out in a car on a dark road nicknamed, “Lover's Lane.” Suddenly a man appears out of nowhere and orders the love-struck teens to get out of the vehicle. Faraday gets out first, at which point he's shot and killed. Jensen makes a run for it and is shot five times in the back. This was the work of the Zodiac, perhaps America's most mysterious serial killer. A maniac still in the crosshairs of law enforcement today, and a man that just spoke again after half a decade of silence. Around six months after that murder, three newspapers received a letter each from a person who claimed he was the killer. In the letters, the person included a cryptogram, that after being cracked seemed to reference a book about hunting, but not animal hunting, it was about hunting humans for sport. His victims, he wrote, would become his slave in the afterlife. “This is the Zodiac speaking,” would become five words that etched themselves into the minds of millions of Americans after more brutal murders and bewildering letters. The killer was playing with the cops, he was needling them, trolling them, so much so that he drove some investigators nearly out of their minds. And then came the unsolvable puzzle, the Zodiac's pièce de resistance, a cipher so perplexing that not even the greatest code breaking minds in the world could solve it, not until now anyway. It's taken 51 years to finally solve the puzzle, and it's revealed a chilling message. Ok, so first you need to know a bit more about the person known as the Zodiac Killer. It's something we've covered in detail before, so we'll give you the abridged version of this rather long and very disturbing tale. SPOILER ALERT: The cops never caught him. Should they have? You can tell us at the end. It's possible that he started his journey as a ruthless killer with those two young lovers, but it's also possible the Zodiac had actually killed before. We may never know for sure, but in a letter, he once claimed to have killed as many as 37 people. The police though, have only ever definitively linked him to the killing of five people. In all likelihood, the Zodiac's body count was way higher. And he might have carried on killing for decades. His last letter came in 1974, and then like a ghost, he just disappeared. That letter contained a postmark saying, “If I don't see this note in your paper, I will do something nasty, which you know I'm capable of.” He then wrote: Me: 37. SFPD: 0. Such letters infuriated the police, especially when he wrote such things as, “I like killing people because it's so much fun.” For the cops, it was only a matter of time before they caught the maniac, but they were wrong, very wrong. It's certain the Zodiac murdered 22-year old Darlene Elizabeth Ferrin and almost killed 19-year old Mike Renault Mageau as they sat in their car in a secluded section of Blue Rock Springs Park in Vallejo, California. The killer pulled up behind them at one point and then drove away. When he returned, he got out of his car and shined a bright light into the couple's car. He shot Ferrin five times and Mageau four times. She died, but he lived to tell the tale. Cops now knew they were looking for a male, possibly in his late 20s or early 30s. He was about five foot eight and on the stocky side. He had brown hair and a roundish face. Mageau might have gotten some details wrong, but who takes notes when you have a gun in your face? How did the police know it was the Zodiac killer? Well, he had the gumption to call them from a payphone only a few blocks away from the station less than an hour after the attack. He told them details about the murder only the killer could possibly know, like what weapon was used. Then he shocked the cops by saying he was also the one who killed the kids on Lover's Lane. So, it wasn't a one-off killer. This was the work of a serial killer. Since the woman was cheating on her husband he was a suspect for a while, but it didn't take long to figure out it wasn't him. The Zodiac was real. And he was far from finished. Ok, so now we need to talk about ciphers and cryptograms. A cryptogram is like a puzzle that contains encrypted symbols. It might look like gibberish, but it has a hidden meaning. To figure out that meaning you need a kind of key to decode it, called a cipher. Anyone can create one with a little bit of research, and if you're the clever sort, you can even create a cryptogram that's next to impossible to decipher. Seeing as it took 51 years to crack one of the Zodiac's puzzles, well, you say criticize him all you want for his brutality, but you can't underestimate the man's brainpower. His first cryptogram was the 408, which is called that because that's how many total symbols are in it. It was published by the San Francisco Chronicle and two other newspapers that were each sent different parts of the puzzle, and the public was asked to solve it. A couple of teachers in California named Donald Gene and Bettye June Harden did just that, and it only took them around 20 hours. Strange, since so-called experts had failed where they succeeded. There's actually a conspiracy theory that the two were the Zodiac, but that's a story for another day. Ok, so in all this cryptogram contained 54 different cipher symbols and 25 letters that are in the English alphabet. The couple worked out that they were looking at what's called a homophonic substitution cipher, which basically means you replace one letter with another, say a D for an M. It gets tricky though when one letter can be replaced by five different letters. They couple cracked it, though, and this is how the decoded message began: “I like killing people because it is so much fun it is more fun than killing wild game in the forest because man is the most dangerous animal of all. To kill something gives me the most thrilling experience, it is even better than getting your rocks off with a girl…” He then goes on about slaves in the afterlife and paradise, so despite being very clever, the Zodiac may also have been suffering from mental illnesses.And he wasn't finished killing. Just over a month later, he struck again. This time he picked on two Pacific Union College students named Bryan Hartnell and Cecelia Shepard. They were enjoying a picnic at a bucolic spot next to Lake Berryessa in California's beautiful Napa Valley. The pair must have received the shock of their lives when they saw what looked like a vision from hell walking towards their very secluded spot. It was a man, about five feet eleven, average weight, wearing what looked like an executioner's hood. They couldn't see his eyes due to the fact he was wearing sunglasses over the mask's eye holes. If that wasn't frightening enough, he was also wearing what looked like a child's bib. On that bib was his now famous crossed circle symbol. The couple were absolutely petrified but didn't move since the maniac approaching them was clasping a handgun. He told them not to worry, and told them a story about being a convict on the run. He subsequently told the young man to tie up his girlfriend with a plastic clothesline that the supposed-convict just happened to have handy. The Zodiac then tied up the woman himself. What happened next is what usually only happens in horror movies featuring college students that drive out to the woods or a lake even though they're warned not to do so by a peculiar-looking gas station owner. The Zodiac started going crazy, stabbing them both in the back. He stabbed the man six times and the woman ten times. Leaving them for the dead, the Zodiac walked about 500 yards to where the couple's car was parked. There he drew his symbol on the door and wrote, “Vallejo/12-20-68/7-4-69/Sept 27–69–6:30/by knife.” That evening the Zodiac got the Napa police department on the phone and told them he really was behind the double murder at the lake. The cops later discovered he'd made that call from a Napa Car Wash that was just around the corner from their department. The cops got a lead from this though, because they managed to get some prints from the phone. Not only that, the kids he stabbed weren't dead. They were discovered inches from death having lost a ton of blood. The girl told the cops what she had seen, but not long after she fell into a coma and died in hospital two days later. The man survived though and told the cops everything he knew. The police also had other clues, such as tire tracks most likely from the killer's car and his size 10 1/2 Wing Walker boot prints. Now cops knew they were looking for a true American psycho. Soon after the Zodiac struck again, this time murdering a taxi driver named Paul Stine with a bullet to the back of the head. Three days later, the San Francisco Chronicle received a letter from the Zodiac containing a piece of Stein's shirt. There was no doubt it was the real deal. The Zodiac said in the letter that the cops could have caught him if they'd been doing their job correctly. He also wrote, “School children make nice targets, I think I shall wipe out a school bus some morning. Just shoot out the front tire + then pick off the kiddies as they come bouncing out.” Just over a week later, someone claiming to be the Zodiac called the Oakland Police Department. The person demanded that either one of two big-shot lawyers, F. Lee Bailey or Melvin Belli, go on a popular local talk show hosted by a man named Jim Dunbar. Belli did just that and appealed for the killer to call in. A man who said he was the Zodiac did call. He said “I need help, I'm sick. I don't want to go to the gas chamber” and he even said he'd meet with Belli, but in the end, he didn't turn up. As you'll soon find out, there was likely more to that call than first meets the eye. This brings us finally to the unbreakable puzzle. Not long after that no-show with the lawyer, the Chronicle received a new communication from the Zodiac. This time it was a cryptogram containing 340 characters, which came to be known as cipher 340, and it proved to be too difficult for the best minds in the world to decipher at the time. People tried for decades from the USA and across the world, but what the Zodiac killer had created was something special, something so annoyingly difficult that after years or trying and failing, the puzzle was forgotten by most code crackers. Maybe it was meaningless, they thought, an assumption that put their frustrated minds at ease. But then in 2006, a global team of crack code breakers took a look at the impossible puzzle again. They knew it meant something, but finding the key was no easy task, and it would end up taking them fourteen years to finally decipher the code. That's dedication. The team included an American software developer named David Oranchak; a computer programmer from Belgium named Jarl Van Eycke, and an Australian mathematician named Sam Blake. Their hard work finally brought the words of the Zodiac to the public. Eycke had actually developed software to break codes, and he had created specifically to crack the one made by the Zodiac. Blake's role in figuring out the cipher was to manipulate the symbols and see how they could be transposed, which Oranchak did the rest. The team said at times they'd get somewhere with the puzzle; they'd find a word, but then they'd discover that what they'd discovered was a false positive, what they called a “phantom.” Then one day the Oranchak announced, “This is a big one. We have a solution for the 340 and it's real.” It hadn't been easy. The team had looked at hundreds of thousands of different manipulations of the text. Then on a Thursday at the beginning of December 2020, a variation of the text showed up in the program. Oranchak said, at first sight, it looked like gibberish but it also contained the words “gas chamber” and the even more Zodiac-esque phrase, “Hope you are trying to catch me.” That was a signature Zodiac taunt. If those phrases were actually part of the correct solution to the puzzle, what the team would then have to do is apply a cipher that had been used for those words to the rest of the symbols in the cryptogram. It was complicated. They realized they had to look at the puzzle and read it in a diagonal fashion. So, they took the symbol in the top left-hand corner and wrote it down, so if it was an “H' they'd write “H”. Then they moved down one and over to the right two spaces. They then wrote down that symbol, which here was a plus sign. They went through the entire puzzle doing this until they'd written down every symbol. What they then ended up with was a completely different looking puzzle. It still looked like nonsense of course, but now they had something new they could put into the code-breaking software. Hmm, the team was rather disappointed after that. Not only did not much of anything come up, but the terms “gas chamber” and “Hope you are trying to catch me” weren't there too. It was as if they'd gone backward. But then Oranchak tried something else. He added the words they suspected were correct - “gas chamber” and “hope you are trying to catch me” to the software as known solutions and let the program run. Pesto, an English message popped up, the words of the grandmaster secret code psycho, the Zodiac himself. “That wasn't me on the TV show.” Was this the Zodiac telling the cops that the guy that had called in to talk to the lawyer was an imposter? Oranchak almost fell out of his chair. After 51 years it was as if the Zodiac had risen from the grave. The team could now decrypt the first part of the puzzle, but the same method of codebreaking didn't work for the other two parts. Since the first part was almost definitely correct, it didn't make sense that the other sections couldn't be solved in the same way. But then they hypothesized that the reason it didn't work, was because the Zodiac had actually made a mistake when he designed the cipher. If that was the case, it was no wonder no one could crack it. You can't open a broken lock with a good key. The team took into consideration that he'd made some spelling mistakes. They corrected the mistakes and then used a slightly different system of the moving down and to the right diagonal reading of the symbols, and they discovered something amazing. It worked. The Zodiac really had made a mistake in his code.