Transcript for How Two Missing Minnesota Sisters Hid in Plain Sight for 2 Years
Tonight it's a strange and extraordinary tale of two sisters who disappeared from their home in Minnesota one evening as their parents were caught up in a hostile divorce. The mother and the girls claiming abuse. But the courts unconvinced. Where did these sisters go? Did their mother have a hand in the disappearance? ABC's Elizabeth vargas has this twisting tale. Reporter: It is 7:00 P.M. On a 30-degree April evening in the suburbs of Minneapolis. While most families are settling in for dinner, one family is about to fracture forever. When two children living at this home vanish. No shoes. No coats. No backpacks. Nothing. Poof. They're gone. Reporter: 13-year-old jianna and 14-year-old Samantha ruckee disappear. The only trace, footprints in the snow. Their parents are embroiled in an ugly divorce and custody dispute. But they insist they are united in their desperation for the girls. Where did they go? Who are they with? And why does our journey begin by asking questions to their mother inside the ramsay county jail? Did you have anything to do with your two daughters running away? No. Do you sit here and think, how did this happen? Clean record, never had a problem. Here you are in jail on a million dollars' bail, what's going on? I have no idea. This shouldn't be what happens in a divorce. Reporter: This divorce is more like guerilla warfare than legal proceeding. But for every documented grievance in this harrowing tale there is documentation too of the good times. Look at this! Reporter: 20 years' worth of home movies featuring both the ruckees in starring roles as an affectionate, feisty couple. And doting, loving parents to their five children. Nikko. Samantha. Jianna. Mia. Gino. Sounds like a busy home. They're wonderful, my dream. Reporter: She says despite smiling faces there was a shocking, ugly secret in the family. Years of emotional and physical abuse by David. What would he do? Throw things, hammers, at me. Blackize, broken ribs. We had to lock ourselves in the bedroom, we were scared. We didn't know how his behavior was going to be one day to the next. Reporter: She claims David didn't just target her but went after the children too. How often did that happen? Once is more than enough. It happened a lot. Reporter: After 20 years of marriage, Sandra says she reaches her breaking point and finally files for divorce. She says frightened for her life, she also gets an order of protection against David. And then she calls police on him at least 20 times. Claiming he continuously violates it. He broke into the house, came running up the stairs, jumped onto the bed that I was at, started choking me, then took a pillow and started suffocating me. Reporter: The children, now ages 8 to 14, remain in Sandra's custody and refuse to even see David. Rebuffing all of his attempts to connect. It's your dad, call me. I would like you to call me back. Call me. Reporter: The family court judge, David Knutzen, appoints an advocate for the children and several therapists, trying to facilitate a relationship with their father. The children say they don't want one. Jianna and Samantha make audio recordings to support what their mother says. This is jianna's voice. Being in the same house with my dad, things were really bad. He was abusive. He had anger issues. He'd always be screaming and yelling. Reporter: But in a surprising twist, the judge determines that there has been no evidence of abuse. And based on the findings from a psychologist he appointed, that it is Sandra who was the real problem here. That the children are showing signs of parental alienation syndrome, meaning the reason the children are adamantly opposed to seeing David is not because he's abused them or their mother, but because Sandra has brainwashed them. I've never done anything but be there for my children. My kids are my life. Reporter: This is where the judge takes a drastic and, for Sandra, devastating step. He orders Sandra out of the house and all five of her children removed from her custody. David's sister tammy becomes the children's temporary guardian. She moves into the ruckee home to take care of them. But the two oldest ruckee girls, Samantha and jianna, are having none of it. On that day the sisters disappear without a trace. What was your reaction? What any mother's reaction would be. I'm concerned, I'm worried. Everything was going through my mind. Reporter: When Sandra's ex-husband David finds out his daughters have disappeared, he is terrified. What was your biggest fear? I mean -- these are young girls. You don't want them hitchhiking. We live about I a truck stop. You think of terrible scenarios. Have you ever raised a hand against Sandra or your children? No. Have you ever struck them? No. Have you ever physically abused them in any way? No. Reporter: David begins to suspect Sandra knows more than she's saying about their missing daughters. Did you think she might have something to do with this? Oh, yeah. Reporter: One month after the girls' disappearance, there is a bizarre twist in the story. They show up. But in a place no one expects. The ruckee girls say they want to be heard -- Reporter: On local television. They met with us at a hotel, we don't know who brought them here. Reporter: The local fox 9 station airs this story. And right there, sitting in front of the reporter, are the two missing ruckee sisters. I'm just really scared it's going to end really badly. Glad to see my girls. But what I was hearing coming out of their mouths was hard. Reporter: As quickly as you can change the channel, the girls are gone again. Vanishing back into the night. The search continues for the ruckee girls. Their parents' epic divorce drags on. Until the judge finally makes his ruling. In a painstaking 60-page order, he drops a bombshell. Awarding full custody of all five children to David, writing of Sandra's allegations of abuse that "The court has not received any evidence to support her very serious allegations." For David it is total vindication. But Sandra's legal troubles were only about to begin. The search for the two missing girls shifts to one of Sandra's staunchest supporters, Deedee evavold, an activist who is vocal about what she says is corruption in family courts. Detectives search her home and find a cell phone photo of one of the girls on a farm. They trace that photo back to white horse ranch. Gina and Doug Dollen own the ranch which offers 90-minute therapy sessions with their animals. Our mission is to reach children and families and bring healing at home through animals. Reporter: They say it was Sandra along with Deedee who dropped the girls off at the ranch one night with no more than the clothes on their back. Then Sandra left and never returned. Days turned into months. And then astonishingly, years. Was it a secret that the girls were here? No, it was not. Everybody knew they were here. Reporter: But it all came to an end last November when authorities arrived at Doug's front door simply following the trail from Deedee's cell phone, not realizing the girls are actually there. When David finally sees the girls for the first time, it is not the reunion he imagined. Were you nervous? I ran out of the room. I started crying. I didn't recognize them. Because -- you know, you know your children, you remember what they sound like. You remember how they looked. I didn't recognize my daughters. Sandra, are you making any comment? Reporter: Sandra is now out of jail, released in February after 130 days behind bars. I do appreciate the air and the sun. I'll say that. Reporter: But she says there was no cause for celebration. I'm in a prison without the bars. What I'm in now. Reporter: As part of her release, Sandra is not permitted to have any contact with Samantha and jianna. She is allowed to see her other children with conditions. As for the girls, David says they are happy to be home and doing well and it might surprise you to hear how David sees his family's future. Will you fight her ability to see the children? This is my children's mother. It's important that they have a mother. Reporter: For "Nightline," I'm Elizabeth vargas in new York.
This transcript has been automatically generated and may not be 100% accurate.