Heather Robinson had long known she was adopted as an infant, after her biological mother died. The couple she knew as her parents were loving, and she was happy growing up in Illinois.
But her world, and that of her parents, came tumbling down in 2000, when all three learned that John Robinson, the man she called "Uncle John," was a serial killer, accused of killing several women in and around Kansas City. The list of victims included Heather's mother, 19-year-old Lisa Stasi, whose body has never been found.
On Friday, in an interview with ABC's "20/20," Heather speaks publicly for the first time about learning the stunning truth.
"When I heard that John had been arrested, I remember [my adoptive mom] running up and down the stairs, panicking. 'How could he do this to us? We're going to go to jail. This is horrible. Our lives are over.'
"That was the first time I ever saw my dad cry," Robinson told the news magazine.
She was 15 when John was arrested in 2000 at his Kansas farm, where police discovered the bodies of several women stored in chemical drums. Two years later, he stood trial for the murders of three other women, including Stasi, in the longest criminal proceeding in Kansas history. He was ultimately convicted of killing eight women and currently lives on death row in a state prison.
For the teenage Heather and her adoptive parents, life changed forever.
The couple didn't know Heather's mother had been murdered. They had been desperately trying to have a child when the husband's brother, John, said he knew of a 4-month-old infant whose mother had killed herself. Using forged adoption papers, John delivered the girl, who he said was named Tiffany, to his brother and sister-in-law. He charged his brother $5,500 in filing fees.
The couple named their new daughter Heather Tiffany Robinson.
Investigators would later learn that John, who was married and had four children, had met Stasi in 1985 at a women's shelter. He called himself John Osborne and said he worked with abused women, and offered the 19-year-old and her infant daughter a new place to live in Chicago, where Stasi could work and Tiffany would receive day care.
Stasi was never seen again. Her family reported her and Tiffany as missing and eventually came to believe both were dead.
Learning her mother had not given her away provided no solace to Heather, she told "20/20."
"It made it worse," she said. "Everything I had fantasized and created about Lisa was completely taken away."
But she had long had felt there was something creepy about her uncle, she said.
As his infamy grew, the teenage Heather retreated farther and farther into herself. At age 22, she won a $5 billion judgment against John, which was designed to ensure he would never profit from his crimes through a book or a movie deal, The Associated Press reported at the time.
Court documents showed her horror at the unwelcome attention she and her family received after John's killings came to light.
"I used to be a very outgoing person," she said in a deposition. "And ever since this has happened, I just crawl up into this little ball, and I do not know why I do this."
She was constantly hounded by journalists, she said, and friends rejected her.
Heather is now a wife and mother, and is devoted to finding her birth mother's remains, she told the news magazine.
"Justice and closure for me is finding her remains and giving her a proper burial," she said. "Closure is knowing exactly what happened, and peace is finally being able to definitively say Lisa was a person, this is what they did to her, this is where she is, and then to be able to finally move on with my life."