Transcript for David and Louise Turpin plead not guilty in California abuse case
us here on a Thursday night. And we begin with those horrifying new tails from that California home. 13 siblings allegedly held captive there by their parents. Tonight here, our first look at those parents, David and Louise turpin, in court, facing charges late today, plea iing not guilty. And prosecutors with a new drips in the gruesome conditions the siblings lived. Investigators say allowed to bathe just once a year. Tonight, the daughter who planned the escape, that plan in the works for two years. ABC's Matt Gutman leading us off. Reporter: Tonight, the man prosecutors portray as a monster is in chains. David, and his wife Louise turpin, pleading not guilty. Accuse of a combined 75 counts of torturing, abusing and imprisoning their 13 children for decades. This is depraved conduct. Reporter: Riverside county district attorney Mike hestrin tonight revealing that for two years the children plotted their escape from the horrors inflicted upon them. This is severe emotional, physical abuse. There's no way around that. Reporter: Hestrin detailing decades of unimaginable punishment that intensified as the years went on. They began to be tied up. First with ropes. One victim at one point was tied up and hogtied. These defendants eventually began using chains and padlocks to chain up the victims to their beds. Reporter: The children allegedly tied or shackled for weeks or months at a time. And starved. The deprivation so severe, the eldest daughter, age 29, weighed just 82 pounds. And officials say their parents would taunt them. They would buy food including pies, apple pies, pumpkin pies, leave it on the counter, let the children look at it but not eat the food. Reporter: Instead, the children were fed a steady diet of cruelty. These pictures show one of their Texas homes. Grime smeared on the stairwells. Human filth on the floors. The district attorney saying the children were allowed to bathe only once a year. Police removing evidence from their California home, recovering hundreds of journals written by the children. I think those journals are going to be strong evidence of what occurred in that home. Reporter: The family allegedly keeping vampire hours. And that may have aided the turpins in keeping the 13 siblings in near complete isolation. The children lacked even basic knowledge of life. Many of the children didn't know what a police officer was. Reporter: And tonight, we're learning that 17-year-old girl who call Ed 911 didn't act alone. She escaped through a window and took one of her siblings with her. That sibling eventually turned back, became frightened and turned back. Reporter: Now, all of the children said to be quote "Relieved" and in good hands. This is all so difficult to believe. Matt gtman back with us from outside the courthouse tonight. And Matt, those children now getting much-needed medical care. But the D.A. Did say today they have suffered cognitive damage? Ruporter: That's right, David. And because some of them have suffered that neurological damage from so many years of starvation and because their isolation kept them so out of the world that many of them didn't even know what medicine was. The state may have to retain control of all 13 of those kids and, as they try to rebuild their lives, their parents face up to life in prison if convicted. David? All right, Matt Gutman tonight. Thank you.
This transcript has been automatically generated and may not be 100% accurate.