The Zodiac Killer.

Benicia, California, December 20th, 1968. At 11 PM, local resident Stella Borges drives along a darkened stretch of Lake Herman Road. Miss Borges comes around the bend and then suddenly sees two bodies lying motionless on the ground. She's shocked, but she knows well enough not to linger. She keeps driving until she can flag down a police car. When the police arrive, they're able to identify the two individuals: Betty Lou Jensen, who's 16 years old, and David Faraday, who's 17 years old, two high school students on their first date.

Detectives examine the bodies and see that David was killed by a single gunshot by his left ear. Betty Lou was shot five times in the back. Police are stunned. Why would anyone commit an execution-style murder? There was no evidence of robbery or sexual assault of any kind, which led them to believe that it might have been a random attack by a stranger.

For seven months, police have no leads. Then, on July 4th, 1969, they receive a shocking phone call. The call is taken by Vallejo police dispatcher Nancy Slover. The caller speaks in a very low, monotone voice and describes where two bodies can be found. He also states that they've been shot with a nine-millimeter Luger. Before he ends the phone call, he says, "I also killed those kids last year."

Police rush to Blue Rock Springs Park in the city of Vallejo, four miles from the first crime scene. When they arrive, they find another young couple inside a car, suffering from multiple gunshot wounds. Twenty-two-year-old Darlene Ferrin is pronounced dead on arrival. Nineteen-year-old Michael Mageau survives. Michael is badly injured but is still able to describe what happened. They were randomly attacked by a stranger who shined a flashlight in their faces right before he fired five shots. He describes the suspect as a Caucasian, about 30 years old, five-foot-eight, 200 pounds, with short, curly hair.

The Bay Area now has a serial killer on the loose. He's claimed three victims so far—nearly four. Almost a month after the second attack, the killer contacts the local press. He includes a strange three-part coded message, or cipher. On July 31st, three Bay Area newspapers receive three virtually identical handwritten letters from someone who claims to be the killer. He demands that the cipher, which is included with the letters, be published on August 1st. He threatens to kill more victims if his demands are not met. The letters are published as demanded.

Then, on August 4th, another letter arrives. This letter, sent to the San Francisco Examiner, says: "Dear Editor, this is the Zodiac speaking." And now, our killer has a name.

A couple in Salinas solved the first cryptogram by using what they call a "crib"—that's where you guess the words and phrases that you think might be in the cipher and then go from there. They believed that the cipher would contain the word "kill," so they looked for pairings of certain symbols that could represent two-letter L's, and they were successful. The message read: "I like killing people because it's so much fun." Once they verified the corresponding symbols for that phrase, the rest of it they solved pretty quickly.

Zodiac's following ciphers are infinitely more complex, and for 51 years, cryptologists don't even come close to solving the remaining ciphers. Investigators wonder if this is one of Zodiac's tricks. Then, in 2020, an all-star group of cryptographers takes on the challenge, hoping to crack one of three unsolved Zodiac ciphers.

"I got involved with this case about 15 years ago," one cryptographer says. "We decided to try to decode a 340-character cryptogram by Zodiac that he'd mailed on November 8th, 1969. We planned to use a method called homophonic substitution, where one letter might be swapped for multiple symbols."

The team creates a powerful software program that processes millions of homophonic substitutions per second. They run this software program for months and months, and not much happens. Then, one day, they run an updated version of the software, and they finally solve the cipher.

"Over time, we were able to identify a few phrases that ended up being part of the right solution—phrases like 'trying to catch me' and 'gas chamber.' Once we saw those phrases, we took a closer look in our experiments, and after a little bit of effort, we were able to unlock the entire message."

The newly decoded message picks up where the last cryptogram left off. It said: "I hope you are having lots of fun trying to catch me. That wasn't 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 paradise all the sooner because I now have enough slaves to work for me where everyone else has nothing when they reach paradise. So they are afraid of death. I am not afraid because I know that my new life will be an easy one in paradise."

"If this one can be solved, then maybe the other two can be solved as well, and maybe that will tell us who the killer is once and for all."

Among those eager to solve the remaining cryptograms is Parisian engineer Faisal Al-Kassar. In 2020, Al-Kassar zeros in on one in particular. He writes his own software to tackle what is thought to be the most difficult cryptogram of them all. On April 20th, 1970, the Zodiac sends a short cipher consisting of 13 symbols, known as the Z13. Because it's so short, it makes it much more difficult to crack. It begins with "My name is," followed by a 13-character cryptogram. So, solving the cipher is actually supposed to provide us with the Zodiac's name.

Once again, modern technology provides a breakthrough. Al-Kassar's software translates the cipher as the letters K-A-Y-R-M-A-N-Y. The translation sounds like gibberish, but veteran Zodiac investigators immediately recognize the name. Detectives who study the Zodiac's letters know that he misspells quite a few words. "We think that's often deliberate, and that K-A-Y-R might just be K-A-Y-E."

This potential solution generates excitement about a decades-old lead. In 1973, Escalon police detective Harvey Hines is assigned to the case and keys in on an ex-convict named Lawrence Kane. Hines begins looking into Kane after noticing that Kane's mugshot bears a striking resemblance to one of the Zodiac sketches. The Zodiac is described as a male between 40 and 45 years old, five-foot-nine, and 165 pounds with dark-colored hair. Lawrence Kane is 45 years old, five-foot-nine, dark hair, and 160 pounds.

Lawrence Kane is a convicted criminal with a long history of arrests for voyeurism, as a Peeping Tom, prowling, burglary, and more. "This is important because criminals don't just jump straight to murder. Their crimes usually escalate." Perhaps most surprisingly, in Kane's background is that in 1942, he's admitted to the Navy's Radio Material School in Chicago, where he's trained in electronics but, more importantly, in coding. This may have also given him access to the military's wing walker boots, which would match the prints at the Lake Berryessa murder site.

Hines next tracks Kane's movements on the days surrounding the Zodiac killings. Kane lives at 217 Eddy Street in San Francisco—that's only two and a half blocks away from where cab driver Paul Stine picked up the Zodiac on the night he was murdered. Hines also discovers that Darlene Ferrin, who was murdered at Blue Rock Springs, worked at Terry's Café, which was just two blocks from Kane's apartment. When Hines interviews Darlene's sister, Pam Huckabee, she recognizes a photo of Kane. Apparently, he often came to the café to harass her sister to the point that Darlene was very afraid of him.

But Hines needs more than circumstantial evidence. Detective Hines contacts Bryan Hartnell, who survived the Zodiac's knife attack at Lake Berryessa and has heard the Zodiac's voice. Hines secretly records a conversation with Lawrence Kane and then plays it for Hartnell. Without hesitation, Hartnell says, "This is the voice of the Zodiac."

Hines next pays a visit to San Francisco police officer Donald Fouke. Fouke rushed to the crime scene on the night that the cab driver was murdered in San Francisco. For years, Fouke claimed that he may have crossed paths with the killer that night. He saw someone suspicious who matched later descriptions, but those descriptions weren't out yet, and he was on his way to a murder scene, so he didn't stop. But Fouke claims he's never forgotten that face. When Hines shows Fouke a picture of Kane, he states that, out of the hundreds of mugshots he's seen since the murder, Kane's picture bears the most resemblance to the man he saw that night.

Three witnesses identifying Kane as the Zodiac Killer—Hines takes his report to Captain Roy Conway and Lieutenant James Huston of the Vallejo Police Department. Hines thinks he's solved the case of the century and is expecting a huge pat on the back. But after Conway and Huston read his report, they basically say, "Thanks, we'll get back to you," and they never do.

Discouraged, Hines calls in one final thing. Of course, cops know a lot of other cops, so Hines sends his report to two San Bernardino detectives he knows and begs them to take a look at it. The two detectives read the report, and they believe it. They think it's good police work. These detectives fly up to Lake Tahoe, go to Kane's home, and ask him about his whereabouts on the night Paul Stine was murdered, Darlene Ferrin, and all kinds of stuff. Kane has an answer for everything. Kane cooperates with investigators, supplying his fingerprints and handwriting samples.

Hines is at home, waiting with bated breath to hear from the two detectives. They eventually call him and say that, based on Kane's answers and the handwriting sample, they concluded that he is not the Zodiac.

Kane passes away in May of 2010. By this time, he's changed his name to Kane (C-A-N-E), but he's never arrested for the murders.