Melissa G. Moore was having breakfast with her father, Keith Jesperson, at a diner when he almost exposed his secret double life.

The high school student, who was gearing up to get her driver’s license, was gushing about getting her freedom. She was also excited to spend time with her father, a trucker who, at that point, was divorced from Moore’s mother.

“I was on the verge of turning 16,” Moore recalled to Fox News Digital. “He made an unannounced visit and asked my siblings and me if we wanted to go have breakfast with him before school started. My siblings had other commitments, so they couldn’t join us. … We talked about what would be my first car. I remember he said he would buy me a Pontiac, and I debated with him.

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“Then the topic started to turn to the next time I would see him,” Moore shared. “He was looking forward to seeing us during the summer break. But the way he spoke, it sounded like it was wishful thinking. … Then he started to say, ‘I need to tell you something, but you’ll tell the authorities.’ It stopped me.

“At first, I thought, ‘It must be the rumors my mother had told me about, that he had been fired for stealing from his employer.’ Did he steal? I kept pressing it, saying, ‘You could tell me.’ He’s like, ‘No, no, I can’t tell you.’ I started to feel sick to my stomach. I went to the bathroom, and when I returned, our food was there. He was ready to change the subject.

“Looking back on that conversation, I feel he knew that his crimes were catching up to him.”

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Moore was 15 when Jesperson, a prolific serial killer infamous for drawing smiley faces in letters to the media and prosecutors, was captured. The case is now the subject of a Paramount+ true-crime drama, “Happy Face,” starring Annaleigh Ashford and Dennis Quaid.

Moore previously shared her story in the bestselling memoir, “Shattered Silence” and the 2018 “Happy Face” podcast. 

“I’m proud of this series because I think the family members of victims will feel seen, and so will family members of perpetrators,” she explained. “I’ve never seen anything quite like this. When you watch a show about a serial killer, they don’t show the complex nature of the relationships that they have with their own family.”

Moore described her childhood as “pretty normal” in rural Washington. Her father, who stood at a towering 6-foot-6, 300 pounds, worked as a long-haul truck driver. Her mother stayed at home with the couple’s three children.

“I grew up in the countryside where we had the freedom to roam,” said Moore. “When my dad would come home from his long-haul truck drives, he was very doting. He was very loving.”

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“He used to love riding his bike, and he always wanted us kids with him,” she shared. “He was a very hands-on father. He would read us bedtime stories. He would play games with us. He would hang out with us as much as possible.”

But there were signs that her home life wasn’t so idyllic. Moore said that when she was 5 years old, she witnessed “animal abuse on our property.”

“My dad would kill animals for sport,” she explained. “He would kill cats. He would kill dogs. That was something that, as a young person … you just feel that’s not right. But it wasn’t something that was really discussed. It was just Keith being Keith. It’s not that we accepted it, but nobody really wanted to acknowledge it.”

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Jesperson was arrested in 1995 on suspicion of killing his girlfriend in Washington state. He eventually confessed to killing eight women between 1990 and 1995 in California, Washington, Oregon, Florida, Nebraska and Wyoming. The victims, who included his girlfriend, acquaintances and sex workers, were sexually assaulted and strangled.

He was arrested just before Moore’s birthday.

“I found out through my mom,” said Moore. “In the series, it’s depicted accurately. I came home from school, and my mother called us siblings together. She had something she needed to tell us. She informed all of us that our dad was in jail and that he was charged with murder. She didn’t give any more details.

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“As an adult looking back, I imagine that … she probably didn’t feel comfortable discussing those details with us.”

News quickly spread in Moore’s hometown. Her friends described seeing Jesperson on TV while watching the news, wearing an orange jumpsuit and chained up. He was called the “Happy Face Killer.”

“I was mortified about going to school and deeply ashamed,” said Moore. “Whenever I turned on the TV, there was my father’s face, flashing across. My friends told me that their parents had seen the news, and they didn’t want them to hang out with me.

“I internalized it,” Moore admitted. “I took it like maybe there was something wrong with me. Maybe the apple doesn’t fall far from the tree. It was the beginning of this deep descent into struggling with my own identity. I internalized his crimes in a way that it wrapped up with my own identity.

“It’s taken me years to reconcile with that,” the 47-year-old added.

Today, Jesperson, 69, is serving several life sentences without the possibility of parole. 

“He has never explained why,” said Moore. “I am still curious why he chose the life that he did and chose to commit these crimes. I believe he felt a deep insecurity within himself and wanted to have control. I would say it was about power and control. … It made this perfect monster.”

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In the show, viewers will see a letter from Jesperson mailed to Moore. She said the scene was accurate.

“He’s written to me from day one since he entered jail, and [those letters] go unanswered,” she said. “I don’t write him back. I’ve collected them, and I’ve given all the letters over to [executive producer] Jennifer Cacicio. She used the letters for dialogue in the series.

“Sadly, her house was among those lost in the California fires. Those letters were burned. They’re gone.”

Today, Moore has a family of her own. In sharing her story, Moore was able to create a network of more than 300 people who are related to killers, speaking with them on the phone and in person for support, People magazine reported. She previously told BBC News that that project gave her “life meaning and direction.”

“I’m not proud of who my dad is, but I no longer feel the need to hide,” said Moore. “I’m no longer attributing his crimes to who I am as a person. And I’m not alone in dealing with these unique issues. … There is no support group for family members of perpetrators. There isn’t really a support group for families of victims. We’re left to ourselves to find other people like us. … They don’t need to be alone in navigating this.”

Speaking out has also helped Moore come to terms with her painful past.

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“My father gave me my greatest sorrow, which is the trauma of growing up with him as a dad,” she said. “I would say the series does a really good job of showing this deep desire within me to have the father who no longer exists, the father of my childhood. He’s no longer here. Maybe he never really existed.”