Transcript for Heather Robinson's biological family discovers she's alive: Part 9
When I found out that Tiffany actually was alive, can only imagine how I would feel if I found out my child was alive. Things were coming out. We weren't even sure that Heather knew that she was Tiffany at that stage. We now have a custody question. There are several families involved. There's Heather's biological mother, Lisa stasi, and her family. Then there is Heather's biological father, Carl stasi, and then there's Heather's adoptive family, the Robinsons. We first reported on this story in 2000, and Chris Cuomo was the correspondent that has been assigned the story. Does my daughter know that I'm alive? I heard they told me yes, but I don't believe that right now, you know. And I believe if she knows I'm alive she'll want to meet me. I feel that. Can you just tell me what kind of house she grew up in? Can you tell me did she have a good life? Was she abused? What does she look like? Anything? Can you tell me anything? What's worse, 15 years of having to deal with a loss, or now, knowing that your daughter's out there? You know, it's probably worse now. At least the 15 years I didn't know, I held that in. Now she's alive, and I'm not seeing her. Carl stasi is angry. He wants to see his daughter and he feels he has every right to see her and be in her life. Lisa stasi's family really strongly believes that they need to do what's best for Heather. If our granddaughter is safe and happy and these people had nothing to do with Lisa's disappearance, and they've taken care of this child, we don't want to take her away. But we want her to know that we're her family and we love her. The Robinsons are now being very protective over Heather, understandably. And they're trying to do everything they can to keep her safe, including not allowing her initially to have any meetings with Lisa stasi's family or Carl stasi. I was still worried that they'd be taking you away from us. You're my daughter. I love you. Do you feel for them? Maybe the family's so petrified of losing their daughter, they don't want to let you in because you hold the key to taking her away. Well, I don't -- I don't care about all that, you know? I care about, it's my daughter. I just want to meet my daughter. My daughter's alive. I have a right to see her, and I want to see her. If we're going to avoid creating a further tragedy in this incident, we're going to have to let Heather Robinson come in to this situation and meet these people on her terms. I want to ask you specifically about you connecting with your biological family. The stasis -- The only biological family I've had anything to do with is Lisa's and that would be her mother. Heather was thrilled at that point, apparently a very joyous, you know, reunion. I did love her. She taught me to not have hate in my heart and to forgive John. Because she did. Wow. And I never could understand. And unfortunately I didn't understand it until after she died. So I never got to have that conversation with her. Did you ever have any kind of relationship with your biological father? I had been openly asked, "Don't you want to know who your biological father is?" I said absolutely not. Why? I just inside, in my heart, I have a dad, I don't need another one. Don Robinson writes this incredibly touching letter to Heather's biological father, Carl stasi, saying that he really wants to do what's best for his daughter and he hopes that they can all understand that and respect that. He asked, you know, Heather really wants to know why was her mother in a shelter? Why weren't you with her? This is really upsetting her. Did he ever answer? No. The stasi family, you know, apparently didn't make any moves to, you know, to pull her out of the home that she had grown up in. The best interest of the child was for her to stay with the family she'd always known. 18 years after Lisa stasi's murder, John Robinson finally goes to trial for the murder of three of his victims. He's facing the death penalty. One of the most horrifying things that happened, the moment when prosecutors played a tape of John and one of his victims. He sat up, and he was straining to get a better look.
This transcript has been automatically generated and may not be 100% accurate.