Three professors, a software engineer and Google employee holed up in a room with a film crew starting last June.
Over the course of about 11 days, the professors and engineers inched closer to cracking an unsolved cipher the famous Zodiac Killer sent to the San Francisco Chronicle in 1969.
University of North Texas professor Ryan Garlick is one of the five code team members, all of whom are featured in the upcoming five-part series, The Hunt for the Zodiac Killer. The series premiere airs 9 p.m. on Tuesday, Nov. 14 on the History Channel.
"Several years ago, we did a class — called symbolic processing — and we focused on the Zodiac-340 cipher," Garlick said.
The Zodiac-340 is a single page of 340 characters — a mix of letters, numbers and symbols — in what looks like felt-tip ink.
Garlick, who has taught computer science at UNT for 14 years, used the cipher in a UNT class in 2008. The small class convened not long after the David Fincher film Zodiac revived interest in the California serial murders. Garlick said the cipher was a useful tool for the students who needed to write software to look for patterns.
"We worked on that in that class and published some things online, and after that, I was contacted by National Geographic," he said.
In 2009, Garlick was featured on National Geographic's Code Breakers, a documentary on codes, ciphers and cryptographs. Garlick said that documentary helped him get a spot on the History Channel's code team for the series.
"There’s a good size community online that is interested in those ciphers," he said.
Garlick joined Kevin Knight, the code team leader in the History Channel series whose day job is a research director and fellow at the University of Southern California's Information Sciences Institute. Knight sharpened his reputation for code breaking as part of the team that solved the famous Copiale Cipher. Knight also wrote the software for CARMEL, a super-computer programmed to think like a killer. The code team includes Sujith Razi, a Google software engineer, Dave Oranchak, a software developer and expert on the Zodiac Killer's ciphers and Craig Bauer, a math professor and cryptographer at York College in Pennsylvania.
"Our part of the series was totally unscripted," Garlick said. "They put us in a room and we'd talk about the ciphers, and these theories would come up and we'd work on them right there."
Garlick said they did long days — from 7:30 a.m. to 7:30 p.m. — and then head to their homes for a few weeks before the filmmakers would bring them back for another day of shooting. In the meantime, the filmmakers had two detectives reviewing the Zodiac Killer's case and a team researching the chilling string of murders that spanned from the early 1960s to the early 1970s. The murderer sent taunting letters and ciphers to newspapers. He bragged about killing, and his letters promised to kill more people — once threatening to kill a busload of children — if the ciphers weren't solved in time. Officials believe the serial killer murdered five people, but the Zodiac Killer bragged about killing 37.
"I was really impressed with the amount of research they did," Garlick said. "They discovered new information, and they found new DNA evidence from the letters."
What's made the Z340 cipher so hard to break? Experts rank the cipher as comparable to the Nazi's Enigma Code as one of the most difficult in history to break. The FBI, CIA and thousands of citizens have tried and failed to solve it.
"If you looked at it, it just looks like a sheet with some letters on it, with symbols mixed in," Garlick said. "If it's a homophonic cipher, that means that each character is a substitute for one or more letters. You go through a process of matching the character to a letter of the alphabet. So you look for a symbol that's used the most in the cipher, and that would be a substitute for a letter that's the most used in English — like 'E' or 'S.' So we run the cipher through the computer program to match those characters and then see what you come up with."
Garlick said the team believes it might have cracked part of the cipher.
"We looked at the cipher in a lot of different ways — up and down [moving from] left to right, up and down [moving from] right to left," Garlick said. "Then someone asked 'what about spirals starting from each corner?' What if you start left to right, then go down to the next line, but go right to left? What about leaving off the last line? You try skipping characters... There’s a guy at the FBI whose theory was that you needed to cut it in half and then paste the bottom half to the top and then read [the cipher] left to right."
The series will revisit the police records and investigation findings, all while keeping tabs on the code team. In a two-minute preview, the series shows the code team comparing the letters of the Zodiac Killer to correspondence from the Riverside Killer, a serial murderer whose homicidal spree began in California in 1986.
Garlick said the identity of the the Zodiac Killer remains a mystery.
"Outside of Jack the Ripper and the JFK assassination, this is the biggest case, the most investigated, and it’s still unsolved," Garlick said. "Now, with the internet and the technology, it's still unsolved. There are 10,000 people working on this, and we have all these tools, we still don't know who did this, and that’s incredible to me."
Garlick said hopes the work the team has done might help lead to the discovery of the killer's identity.
"On the map he sent to the San Francisco Chronicle, he put his symbol over Mount Diablo, and said he had a bomb buried out there," Garlick said. "It's really possible that there's still a bomb out there. There's also the possibility the Zodiac is still alive... A few of his victims are still alive. I'd like to know who did all this, and there are obviously a lot of other people who want to know who the Zodiac Killer is or was. If the case was solved, it would help a lot of people."
LUCINDA BREEDING can be reached at 940-566-6877 and via Twitter at @LBreedingDRC.
FEATURED IMAGE: The code team tasked with trying to solve the Zodiac 340 cipher, the message sent to a California newspaper by the Zodiac Killer in 1960s-70s. Pictured, clockwise from the left: University of North Texas professor Ryan Garlick; University of Southern California Kevin Knight (standing) Google Engineering Sujith Razi (seated, background) and Craig Bauer, a math professor at York College in Pennsylvania. Photo courtesy of the History Channel/A&E.