Zodiac killer still haunts victim's sister as surprising new theory emerges: 'I'm still hoping for closure'

For over 50 years, Kris Chambers has wondered who murdered her sister.

It was 1969 when Darlene Ferrin, a popular waitress in Vallejo, California, became one of the victims of the self-proclaimed "Zodiac Killer." The identity of the murderer, who killed at least five people in California during the ‘60s, is still unknown today.

Chambers told Fox News Digital that her parents passed away without ever knowing who took their daughter’s life. But she’s hopeful that in her lifetime, answers will finally be revealed.

"I’m still hoping for closure," said Chambers. "I think the truth can still be found out there. I haven’t given up."

Chambers has come forward for a new true-crime docuseries on Peacock titled "Myth of the Zodiac Killer." It aims to investigate a theory made by professor Thomas Henry Horan — that the Zodiac was nothing more than a hoax. Horan's book "The Myth of the Zodiac Killer: A Literary Investigation" theorizes that there were possibly multiple murderers that wreaked havoc in the Bay Area and the slayings may not have been connected.

The special, directed by Andrew Nock, features interviews with loved ones, investigators, experts, a witness and critics who have questioned Horan’s idea, as well as Horan himself.

Chambers said she’s heard it all over the years. But she doesn’t want to rule out a possibility that could lead to answers.

AIR FORCE VET IDENTIFIED AS ZODIAC KILLER SUSPECT BUT FBI DIDN'T ACT ON DNA PROOF, GROUP CLAIMS

"I have to look at all of it," she explained. "I have to keep an open mind because nothing else has worked. But it’s hard. Whenever something comes up in the newspaper or online, I start all over again — thinking about the what-ifs. I’m hoping someone out there may know something — anything to help solve this crime."

"I want to find out who killed my sister," Chambers said, fighting back tears. "And there are other families who are still grieving. Darlene isn’t just a character in a story. People sometimes forget these are real people. And their families are still hurting… Now, I have read some theories that are just outrageous. Sometimes you can’t think about it or even look at them. But if you get a good group of people together, and they all start thinking a little differently, maybe it might bring out something good."

The first confirmed slayings took place on Dec. 20, 1968. High school students Betty Lou Jensen, 16, and David Arthur Faraday, 17, were found shot by passing motorists in a desolate area that was known as a lover’s lane. Jensen, who was pronounced dead at the scene, had five bullet wounds in her back. Faraday had a bullet wound in his head but was still clinging to life. He succumbed to his injuries on the way to the hospital.

More than six months later, on July 4, 1969, a similar attack occurred four miles away. Ferrin picked up her pal Michael Mageau, 19, and was parked at Vallejo’s Blue Rock Springs Park. A vehicle pulled into the lot around midnight and then left, only to return minutes later, History.com reported. According to the outlet, the driver got out of the car and shot the pair.

Mageau, who was hit in the jaw, shoulder and leg, survived. That same night, a man called the Vallejo Police Department and claimed responsibility for the shooting, as well as the previous murders along Lake Herman Road, the San Francisco Examiner reported.

CRUZ REACTS TO REPORT REVEALING ZODIAC KILLER'S IDENTITY, AFTER VIRAL JOKE CLAIMING HIM AS A SUSPECT

Just a few weeks later, the first letters allegedly written by the killer arrived at several San Francisco newsrooms. He taunted the press and police, boasting about his crimes and warning he’d strike again. The letters came with ciphers which he claimed held his true identity. One long cipher was solved by a Salinas schoolteacher and his wife. It said little beyond, "I like killing because it is so much fun." While correspondence continued to arrive intermittently until 1974, the authentication of many of the letters has been debated over the years, the U.K.’s Independent reported.

On Sept. 27, 1969, college students Cecelia Ann Shepard, 22, and Bryan Calvin Hartnell, 20, were relaxing along the shore of Lake Berryessa, History.com reported. A man wearing a hooded costume with a white cross-circle approached them, holding a gun. He bound their wrists before stabbing Hartnell six times, the outlet reported. Shepard was stabbed 10 times. The stranger then called the Napa Police Department to report "a double murder." Hartnell survived and Shepard died two days later.

Then on Oct. 11, 1969, cab driver Paul Stine picked up a fare heading to the Presidio Heights neighborhood, the outlet shared. At the intersection of Washington and Cherry Streets, the passenger shot the 29-year-old in the head. The killer ripped off a piece of Stine’s shirt and mailed it to the San Francisco Chronicle with a letter from "The Zodiac."

Chambers said she was 16 when her sister died. She later moved out of Vallejo to escape the media scrutiny that followed her family.

"I got an unlisted number and would tell [reporters] not to call back," she said. "My niece was only a year and a half when her mother was killed. I didn’t want them to learn anything about me. I just shut everything out."

"My sister was full of life," Chambers reflected. "She was extremely friendly. She had lots of friends and was wonderful to be around. She was a great gal. She was always smiling and very loving. I remember she would pick me up, get me out of the house, and take me places… How did I cope with [her death]? I had my family with me constantly."

According to Chambers, she never connected with Mageau despite her efforts.

MEXICAN AUTHORITIES HUNTING FOR 'TED BUNDY'-LIKE SERIAL KILLER AFTER 3 FOUND DEAD IN TIJUANA

"I remember he couldn’t walk or talk for a long time," she said. "I never could get him on the phone or talk to him in person. I tried a few times. I think maybe one of my sisters might have talked to him. But he was really messed up. He wouldn’t talk about it."

There have been other possible victims during the ‘60s and ‘70s. In 2021, the FBI announced that the Zodiac Killer case is "open and unsolved."

Over the years, the case spawned numerous books, movies and documentaries. Both professional and amateur sleuths have also attempted to unmask the killer.

In 2021, a team of specialists who investigate cold cases, known as The Case Breakers, claimed that the Zodiac Killer was Gary Francis Poste, who passed away in 2018. However, no one has ever been charged or identified in connection with the murders.

At the time, Fox News Digital reached out to the Vallejo Police Department and the FBI and unsuccessfully tried reaching out to relatives of Poste. The San Francisco Police Department said it was unable to speak about potential suspects in the Zodiac case because it remains an ongoing investigation.

Arthur Leigh Allen, who has been frequently listed as a suspect, died in 1992.

INFAMOUS LONG ISLAND SERIAL KILLER SUSPECT BEHIND GILGO BEACH MURDERS IN CUSTODY: OFFICIALS

Previously in 2020, a team of code-breakers cracked a 340-character cipher that was sent to the San Francisco Chronicle. It read: "I hope you are having lots of fun in trying to catch 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."

David Karabinas, executive producer of "Myth of the Zodiac Killer," told Fox News Digital that it’s important to look at the case with different perspectives.

"Is it possible that there could be one singular person who’s such a criminal mastermind who’s been able to elude the authorities, independent investigators and citizens for over 50 years?" he said. "No one can decipher him, no one can figure it out. Or is it possible that there’s another answer? And maybe that other answer is what’s keeping us from actually getting to the truth… I think everyone is trying to find one killer, one person who is responsible for all of these incidents. But in doing so, we’re limiting the pool of people we can look at. And if we do that, we can miss a potential suspect… It’s keeping us from potentially looking at everybody that we should be looking at."

"What we want to do with this documentary is spark a new conversation," he continued. "… Maybe if we look at it from a different perspective, we can find closure."

Even Ferrin’s ex-husband, Jim Phillips, appeared in the documentary.

"His interview is very weird and compelling," Karabinas admitted. "But I think that’s the point… What other rocks have been unturned?"

ALLEGED CALIFORNIA KILLER LIKENED TO TED BUNDY ARRESTED FOR DEATHS OF MEXICAN SEX WORKERS

For Chambers, time is ticking. But it’s not too late.

"A lot of the investigators have passed on," she said. "But there are people who still care. And gosh, if it could just spark something in someone."

Chambers paused.

"She was just a 22-year-old girl who loved life," said Chambers about her sibling. "She was a good mom and a good wife. It was hard on my parents… They’re both gone now… But maybe this might get some good people to come up with something."

"Myth of the Zodiac Killer" is currently available for streaming. Fox News Digital's Louis Casiano and The Associated Press contributed to this report.