The children of David and Louise Turpin endured years of severe child abuse, including being tied up with ropes and chains for weeks, denied food and only allowed to shower once per year, the Riverside County district attorney said Thursday.

The dozen oldest children were so severely malnourished they faced muscle-wasting, DA Mike Hestrin said, and have suffered cognitive impairment and nerve damage as a result of “extreme and prolonged physical abuse.”

“One of the children, at age 12, is the weight of an average 7-year-old,” Hestrin said. “The 29-year-old female victim weighs 82 pounds.”

David Turpin, 56, and Louise Turpin, 49,  have been charged with 12 counts of torture and other criminal counts, and they face 94 years to life in prison if convicted as charged. The youngest of the couple’s 13 children, a 2-year-old, was not starved and thus was not included in the torture charges, Hestrin said.

The Turpins pleaded not guilty at a hearing Thursday afternoon in Riverside, where the judge denied a public defender’s motion to prevent filming in the courtroom. Their bail was set at $12 million each.

The judge noted news coverage of the case “literally spans the globe.”

In a statement, Hestrin said is was “one the most disturbing cases” he’s seen in more than two decades as a prosecutor.

The parents would buy food for themselves, including apple and pumpkin pies, and allow the children to see it but not eat it, the DA said at the news conference.

“This is severe physical, emotional abuse,” Hestrin said. “This is depraved conduct.”

One of the victims, a girl under age 14, was “touched in a lewd way” by David Turpin, who used force or fear, Hestrin said.

The children range in age from 2 to 29, with six of them minors and seven of them adults. All 13 of the children have first names that start with the letter “J,” according to the 10-page, 38-count criminal complaint.

Hestrin’s morning news conference in Riverside provided new details of the allegations in a case that has drawn international attention to Perris, a suburban town some 60 miles east of Los Angeles. Hestrin called the new information “just a snapshot.”

The children were found in the Turpins’ home Sunday after a 17-year-old sibling escaped through a window, called 911 on a deactivated cellphone and summoned deputies. Authorities have praised her courage, and said she was so emaciated she looked like a 10-year-old.

Hestrin said the teen had worked with her siblings on a plan to escape for more than two years. One of the teen’s sisters escaped with the 17-year-old but turned back in fear, Hestrin said.

Many years ago, the children said they began being tied up with ropes “as a punishment,” Hestrin said. One victim escaped being hog-tied and then the parents allegedly began using chains and padlocks to chain them to their beds.

They were locked in different rooms and were frequently beaten, Hestrin alleged, also describing “strangulation.” He stressed the investigation is ongoing.

The children were so poorly educated in their state-registered home school that many of them didn’t know what a police officer was nor what medication was, Hestrin said.

“They lack a basic knowledge of life,” Hestrin said.

Religion, he said, did not have a role in the treatment of the children.

When deputies knocked the the Turpins’ door on Sunday morning, the Turpins unchained two of the three children, but one – a 22-year-old – remained chained, according to the DA. An 11-year-old and 14-year-old were unchained as deputies stood at the door, Hestrin said.

The punishments would last for weeks or months, and the victims were not allowed to go to the bathroom, the DA said, citing evidence in the home. If they were found to have washed their hands above the wrist, they were accused of “playing in the water” and then were chained, Hestin said.

The family slept during the day, going to bed before dawn, and was awake through the night, Hestrin said. That helped the Turpins’ behavior escape detection by neighbors.

The abuse began when the family resided in Fort Worth, Texas – where the children lived apart from their parents, who dropped off food for them. The treatment continued after the family moved to Murrieta – also in Riverside County – in 2010. They moved to Perris in 2014.

“The abuse and severe neglect intensified over time and intensified as they moved to California,” Hestrin said. “It was what started out as neglect – became severe, pervasive, prolonged child abuse.”

None of the children have ever seen a dentist and they have not been to a doctor in four years, though they are believed to have been born in hospitals. They were denied toys, though toys were found in the house in their original packaging, Hestrin said.

At least one of the older male victims attended classes, and Louise Turpin waited outside class for him, Hestrin said. It’s not clear where he took the courses or when.

The children were permitted to write in journals, and investigators are looking through “hundreds of them,” he said. They are expected to provide “strong evidence” of what happened in the home, Hestrin said.

Asked if the parents have indicated why they treated their children this way, Hestrin said he couldn’t comment about that.