WHAT DO LETTERS FROM DEATH ROW INMATE REVEAL? Ted Bundy’s cousin recounts a series of condescending letters he sent from the execution chamber — the contents of which sent chills down many people’s spines….

What started as one letter led to years of correspondence between Edna Martin and her cousin, infamous serial killer Ted Bundy, who confessed to killing more than 30 young women during the 70s.

Martin, 74, recalls sending her first letter to Bundy on Sept. 9, 1980, asking him what he thought of Ann Rule’s book, The Stranger Beside Me, which chronicled Rule’s friendship with Bundy and was released in August of that year.

“He wrote back that [the book] was full of falsehoods and half-truths,” Martin tells PEOPLE.

She says he also told her he was “excited” to get her letter and that it had been five years since they last saw each other.

“He said that was BC, or before court, cops — and AD, or after damnation,” says Martin, who went on to write a memoir about her life with Bundy called Dark Tide: Growing up with Ted Bundy, which was released in July 2024.

Martin is also appearing in Oxygen’s new documentary, Love, Ted Bundy premiering Sunday, Feb. 15 at 6 p.m. ET/PT.

Martin, an insurance broker in Washington state, says she started to send more letters to Bundy while he was on death row — after he was convicted of killing two college co-eds in Florida State University’s Chi Omega sorority house and raping and murdering a 12-year-old girl — because she wanted him to admit what he did.

“I still felt like I may have some influence on him because of our close relationship,” she says. “And I thought, ‘Maybe, maybe I might be able to get him to budge.’ We were really good friends, and we hung out together a lot,” she says. “I trusted him wholeheartedly. And that’s what was so incredibly shocking to find out that someone you know, [and] really trusted and exposed my friends [to] could be this beast.”

The two grew close while she was attending the University of Washington and Bundy — who was five years older than her — was working for Republican Gov. Dan Evans’ reelection campaign and went undercover to attend rallies of Evans’ opponent.

“We loved when he would show up because he always brought a bag of food and we were starving college students,” says Martin. “And he was a real popular guest. We’d all kind of gather around him in a circle because he was very engaging. He’s just got sparkly eyes and a big smile and he’s a good storyteller. And we looked at him like he was a very successful person.”

Martin had no idea at the time that Bundy was responsible for a series of brutal attacks on women in the area, including fellow University of Washington student Karen Sparks, who Bundy attacked and left for dead in 1974.

Martin recalls Bundy told her that the attacks were “terrible.”

“The implication was ‘I’m just around the corner if you need anything,’” she says.

At the end of the day, Bundy declined to provide more details about the killings to his cousin in the letters they exchanged.

“I said, ‘why would you develop such a deep rage and hatred that you would feel so overwhelmed that you would have to kill ruthlessly?’” she recalls. “His response was ‘I won’t disregard your accusations completely … I will say this much, I have not killed anyone.’ And then he goes, and he quotes a Bible verse to me.”

“He was pretty patronizing,” Martin says, reflecting on the letters.

“He said, ‘you don’t know me anymore and you need to get to know yourself first before you can know me.’ He implied that I didn’t know all the facts,” she says. “One of the quotes that he wrote to me was, ‘I have no guilt, remorse, or regrets over anything I’ve done.'”

Despite this, she says Bundy — who was executed on Jan. 24, 1989 at Raiford Prison in Florida — always signed the letters with “Love, Ted.”

“Ted was two people,” she says. “He was one person to his family and friends, and obviously he was something altogether terrifyingly different to his victims. I don’t think he felt like he ever wanted to take that mask off with me.”

Love, Ted Bundy premieres on Oxygen on Sunday, Feb. 15 at 6 p.m. ET/PT.