'Happy Face Killer's' Daughter Melissa Moore Comes Face-to-Face With Sister of Father's First Victim "I'm ashamed that he's my dad," Melissa Moore told the sister of the victim.

 -- Melissa Moore, the daughter of the notorious serial killer in the ‘90s known as the “Happy Face Killer,” has made it her mission to speak out on behalf of relatives of other serial killers.

But for the first time ever, Moore decided to meet face-to-face with a relative of her father’s first victim.

Moore’s father is Keith Jesperson, who earned the nickname “Happy Face Killer” for the smiley face drawings he included on letters, in which he bragged about killing eight women in a spree that began in 1990. Jesperson, a long-haul truck driver, carried out his killings over the course of five years and went undetected until he turned himself in. Jesperson has been serving three consecutive life sentences in Oregon’s state penitentiary since 1995.

Since going public with her story, Moore, now 36, says she has corresponded with more than 100 children and relatives of mass murderers, from the daughter of the BTK serial killer to the Boston Strangler’s family. She meets with the families of mass murderers, shares their stories, and brings some together with relatives of the killers’ victims on a new TV series on LMN called “Monster in My Family." LMN is owned by A&E Networks, a joint venture between the Disney-ABC Television Group and the Hearst Corporation.

"It shows that these people that are monsters in society are loving fathers at home," she told ABC News "20/20." "They’re the ones playing with their children... They’re loving, they’re doting, they’re caring, but then there’s a whole another side."

But Moore is still searching for closure from her father’s horrific past.

Cameras were there as Melissa and her mother met with Michelle White, the sister of her father’s first victim, 23-year-old Taunja Bennett, whose murder was the one Jesperson insisted on getting credit for, writing on a rest stop bathroom wall, “Jan 21 90... Killed Tanya [sic] Bennett in Portland... Two people got the blame... So I can kill again.”

“I’m ashamed that he’s my dad,” Moore told White during their meeting at White’s home. “I’m ashamed that he has no remorse. I’m ashamed of how he treated your sister and what he did to your sister.”

White said the publicity Moore received when she went public with her story as Jesperson’s daughter, including the book she published in 2009 called “Shattered Silence: The Untold Story of a Serial Killer’s Daughter,” reopened old wounds and put her family through more pain.

“It’s all about your dad,” White said. “And, you have done a book about how you grew up but this person had a life and you, yourself, had made it more public.”

“We have to relive every moment from the time [Taunja] walked out that G-- ---- door, that I should have stopped her,” she continued.

But as the meeting between the two women came to an end, White offered Moore a bit of solace.

“But don’t ever feel guilty of what your dad did,” White told her. “Don’t ever feel guilty … just because you came from him, doesn’t mean you did it.”

Although Moore said she understood White’s anger, she was reassured by her kind words at the end of their meeting.

“It’s definitely a gift,” Moore said. “And what’s hard is like I want to accept that gift, but I feel almost unworthy to accept it because of who I’m related to.”

Moore and two other daughters of notorious killers are profiled in the July 2015 issue of Marie Claire, where they all say they had to learn to separate their fathers' actions from their own lives. Moore said she wanted to meet White to send her condolences.

"I'm not apologizing on behalf of my dad. I'm apologizing as a caring human being to another caring human being," she told the magazine.

Moore has not spoken to her father in over a decade. Despite her quest to find peace, she said she still can’t seem to forgive herself for what her father did to his eight victims and their families.

“Being the daughter of a serial killer puts everything into question, ‘Am I worthy? Do I have a right to exist?’ When he took so much away from other people,” Moore told "20/20." “If I’m happy is that a slap in the face to the victim’s families? I don’t want it to be.”