The mother of 13 malnourished children and young adults who were held in filthy conditions, some chained to furniture, was "perplexed" when deputies arrived at the family's Southern California home, a sheriff's official said Tuesday.

The deputies had been summoned by a 17-year-old daughter who jumped out a window and called 911.

Riverside County sheriff's Capt. Greg Fellows described the reaction of the mother, Louise Anna Turpin, 49, without elaborating. He said he did not know how the father, 57-year-old David Allen Turpin, reacted.

The situation at the home in Perris, about 130 kilometres southeast of Los Angeles, was discovered when the daughter escaped early Sunday, Fellows said.

The teen, who was so small that deputies initially thought she was 10 years old, showed them photographs that led them to believe her story and go to the home to check on the family, Fellows said.

"The conditions were horrific," he said.

The children, ages two to 29, are all believed to be the biological offspring of the Turpins, authorities said.

Fellows said the investigation has so far found no indication of sexual abuse but that the conditions amounted to torture.

"If you can imagine being a 10-year-old and being chained to a bed ... I would call that torture," he said.

First interaction with authorities

The family had lived in Perris since 2014, and deputies had never been to the residence previously for any reason, Fellows said.

Social workers had never visited either, said Susan von Zabern, director of the county Department of Public Social Services.

The seven adult children were being cared for at Corona Regional Medical Center, said CEO Mark Uffer. He described them as small and clearly malnourished. "It's hard to think of them as adults when you first see them because they're small."

He said the siblings were being fed and were listed in stable condition.

Capt. Greg Fellows of the Riverside County Sheriff's Department, answers questions from the media on Tuesday, in Perris, Calif. (Stan Lim/Los Angeles Daily News/Associated Press)

"They're very friendly," he said. "They're very co-operative, and I believe they are hopeful that life will get better for them."

The parents were each held on $9-million bail and could face charges including torture and child endangerment.

It was not immediately known if they had attorneys. They were scheduled to appear in court later Thursday.

State Department of Education records show the family home has the same address as Sandcastle Day School, where David Turpin is listed as principal. In the 2016-17 school year, it had an enrolment of six.

'I would call that torture,' says City of Perris police chief 2:11

Neighbours shocked

Neighbours in Perris, where modest but well-maintained homes are tightly packed on suburban streets, said they were stunned by the arrests.

Andrew Santillan, who lives around the corner, heard about the case from a friend.

"I had no idea this was going on," he told the Press-Enterprise newspaper of Riverside. "I didn't know there were kids in the house."

Other neighbours described the family as intensely private.

None had any idea of horrors allegedly visited upon couple's young and adult children for years 1:03

A few years ago, Robert Perkins said, he and his mother saw a few family members constructing a nativity scene in the Turpins' front yard. Perkins said he complimented them on it.

"They didn't say a word," he said.

3 marriage renewals

Social media photos show the family at Disneyland and Las Vegas. The most recent shots, from 2016, show the parents beaming after they apparently renewed their wedding vows and posed with an Elvis impersonator.

The Turpins appeared to have had marriage-renewal ceremonies at least three times, in 2011, 2013 and 2015, at an Elvis Presley-themed chapel in Las Vegas, according to the chapel's YouTube page.

One video shows 10 female children in matching purple plaid dresses walking down the aisle ahead of Louise toward David, who waited at the altar with two male children in suits. A third male child dressed in a suit appeared later in the video during various dance performances with the Elvis impersonator and the family.

An Elvis Chapel representative did not immediately respond to a request for comment.

A joint Facebook page that appeared to have been created by the parents showed the couple at the same chapel dressed in wedding clothes, surrounded by the 13 children.

Grandfather surprised at arrest

James Turpin, of Princeton, W. Va., said Tuesday that he was surprised by the news reports about his son David. All 13 children are David's biological children. None are adopted, he said.

Turpin said he first heard about the matter Monday night in a call from a reporter. He declined to talk further.

"We're going to try to get to the bottom of it," he told The Associated Press.

Members of the media wait outside the home where authorities said an emaciated teenager led deputies to her 12 brothers and sisters, who were locked up in filthy conditions. (Alex Gallardo/Associated Press)

He and his wife, Betty, told Wheeling, W. Va., television station WTRF that David grew up in southern West Virginia.

Louise Turpin's sister, Teresa Robinette, told NBC News, "We always thought she was living the perfect life," and that her husband was "treating her like a queen." Robinette and her brother, Billy Lambert were interviewed in Knoxville, Tenn.

"She would tell us they went to Disneyland all the time, they would go to Vegas," Robinette added.

However, the siblings told NBC they hadn't seen their sister in nearly two decades. What little contact they had with Louise was by phone.

Lambert said they had no idea anything like what the police have reported was going on. "If we knew, we would have fixed the situation," Lambert said.

Moved to California in 2011

David Turpin left his engineering job at Lockheed Martin Corp. in 2010, a company spokeswoman told Reuters.

The family moved to Southern California in 2011 from Johnson County, Texas, near Dallas, according to property records.

The Turpins filed for bankruptcy that same year, stating in court documents that they owed between $100,000 and $500,000. At that time, Turpin worked as an engineer at Northrop Grumman and earned $140,000 annually and his wife was a homemaker, records showed.

A Northrop spokesman declined to say whether Turpin was currently employed there, Reuters reports. "We are deeply troubled by the nature of the allegations against Mr. Turpin," Northrop's Mark Root said in a statement.

Their bankruptcy lawyer, Ivan Trahan, told the New York Times he never met the children but the couple "spoke about them highly."

"We remember them as a very nice couple," Trahan said, adding that Louise Turpin told him the family loved Disneyland and visited often.