RIVERSIDE, Calif. - A judge heard further arguments Thursday as he weighed whether a California couple will face trial on allegations of subjecting most of their 13 children to years of filth, starvation and bizarre abuse that included feeding them moldy pies and sometimes caging them as punishment. David and Louise Turpin appeared for a second day at a preliminary hearing.

Horrific testimony of starvation, squalor and bizarre punishment was presented Wednesday. Photos showed two pale, malnourished girls shackled to bunk beds. Their sister, who surreptitiously snapped the photos, was heard pleading in a 911 call for someone to come and save her siblings.

Louise and David Turpin at a preliminary hearing June 20, 2018 in Riverside County Superior Court CBS LA reporter Nicole Comstock via Twitter

"They will wake up at night and they will start crying and they wanted me to call somebody," the 17-year-old tells the dispatcher in a quivering, childlike voice.

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David and Louise Turpin have pleaded not guilty to torture, child abuse and other charges. Each is being held on $12 million bail and could face up to life in prison if convicted.

The couple was arrested in January after their 17-year-old daughter, who spent two years planning an escape, climbed out a window and left the home in Perris, then called 911. By the time police arrived at the house 70 miles southeast of Los Angeles, two girls, 11 and 14, had been hastily released from their chains, but a 22-year-old son remained shackled.

The young man said he and his siblings had been suspected of stealing food and being disrespectful, Riverside County Sheriff's Det. Thomas Salisbury said. The man said he had been tied up with ropes at first but later, after learning to wriggle free, was restrained with increasingly larger chains on and off over six years.

Prosecutors also showed photos of the girls that their 17-year-old sister took with an old cellphone before fleeing. The photos drew gasps from some court attendees.

Sheriff's deputy Daniel Brown said one daughter told him that she knew her sister had contacted police when she heard a knock at the door and saw flashing lights outside the window.

"She said she was finally going to become free," Brown said.

Investigators testified that the Turpin children, ranging in age from 2 to 29, lived mostly in locked rooms and were deprived of food, toys, games, schooling and most outside contact, barring two family visits to Disneyland and Las Vegas.

The oldest son attended classes at a local community college but investigators have said his mother waited outside the classroom and immediately brought him home after classes.

Senior investigators with the county district attorney's office testified that doctors and medical records showed some of the children were severely malnourished and had muscle wasting, with some adult children being 32 pounds underweight.

The 11-year-old girl who had been shackled to her bed had stunted growth from malnourishment and her arms were the size of an infant's, investigator Patrick Morris said.

In her 20-minute 911 call, the 17-year-old who escaped told the dispatcher: "We don't really do school. I haven't finished first grade."

The girl told sheriff's deputy Manuel Campos that she hadn't bathed in a year and that she didn't know the date or the month, he testified.

About two years ago, her mother choked the girl for watching a Justin Bieber video on a cellphone borrowed from her sister, telling her: "You want to die and go to hell," according to Campos.

There was no breakfast, and recently lunch and dinner had been combined into one meal that included peanut butter and bologna sandwiches, a frozen burrito and chips.

The girl said she recently had started refusing the peanut butter sandwiches "because she starts to gag and starts to throw up," Campos testified.

As the preliminary hearing continued Thursday, the seven adult children were in a separate courtroom at a guardianship hearing.

Jack Osborn, a lawyer for the 13 children, said no decision was reached on appointing the Riverside County Public Guardian as their long-term conservator. Bailiffs cleared the hallway after the appearance to clear a passage for the adult siblings who were ushered out of view.