Early Sunday morning, a 17-year-old girl escaped from the residence, located in the 100 Block of Muir Woods Road and called 911 from a cellular device she managed to take from the home, investigators said.
That teen told the 911 operator that she and her 12 siblings were being held captive in their home by their parents.
When investigators from the Perris Police Department and the Riverside County Sheriff's Department met with the girl, they said she looked emaciated and only 10 years old, though she was 17.
After interviewing the girl, investigators contacted her parents, 57-year old David Allen Turpin and 49-year old Louise Anna Turpin at the home from which the teen escaped.
Further investigation revealed several children shackled to their beds with chains and padlocks in dark and foul-smelling surroundings. However, the parents were not able to immediately provide a reason why their children were restrained in that manner.
The Turpins lived in the middle class community of Perris, California, 70 miles east of Los Angeles. Authorities believe their 2400 square foot house was more a cruel dungeon.
Deputies located what they believed to be 12 children inside the house - but were shocked to discover that seven of them were actually adults, ranging in age from 18 to 29.
The victims appeared to be malnourished and very dirty.
There were 13 victims total -- 12 in the house, and one who escaped and called 911. The victims, who ranged in age from 2 to 29 years old, were transported to the Perris Station and interviewed.
Both parents were detained and transported to the station for further investigation. Child Protective Services and Adult Protective Services arrived to assist in the investigation. The victims were provided with food and beverages after they claimed to be starving.
Both parents were interviewed and subsequently transported to the Robert Presley Detention Center. They were arrested on suspicion of torture and child endangerment.
Records show the father registered his home as a private school called Sandcastle Day. There are questions as to whether investigators ever checked on the home-schooled victims.
Neighbors 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 of Riverside. "I didn't know there were kids in the house."
Other neighbors described the family as intensely private.
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.
The Turpins filed for bankruptcy in 2011, stating in court documents they owed between $100,000 and $500,000, The New York Times reported. At that time, Turpin worked as an engineer at Northrop Grumman and earned $140,000 annually and his wife was a homemaker, records showed.
Their bankruptcy lawyer, Ivan Trahan, told the 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.
Bail was set at $9 million each.
If you have any relevant information about this ongoing investigation, you're urged to contact Investigator Tom Salisbury at the Perris Station by calling (951) 210-1000 or emailing PerrisStation@RiversideSheriff.org.
(The Associated Press contributed to this report.)