The Turpin parents wanted more children in a twisted plan for fame, family says.

Ever since 13 children were rescued from their parents’ home in California last Sunday, the world has watched an endless torrent of disturbing details emerge with one, resounding question.

‘Why?’ 

In all the horror that Louise Turpin, 49, and David Turpin, 57, allegedly inflicted upon their children – including starving, strangling, and chaining them to bedposts – the couple’s motivation for the alleged abuse is not clear.

“Sometimes in this business, we are faced with looking at human depravity and that is what we are looking at here,” Riverside County District Attorney Mike Hestrin said in a press conference last Thursday.

No one can understand it. How these children, aged two to 29, emerged from the home so malnourished they look prepubescent with their muscles wasting away. That they’d been planning for two years to escape, until one of the daughters finally had the courage to climb out a window and call for help. Responding police officers thought she was 10. She was actually 17.

But now, one explanation – if there is such a thing – is on offer.

LISTEN: We discuss the world’s current fascination with true crime. Post continues after audio.

According to Louise’s half-brother Billy Lambert, 30, who is a self-employed mobile home remodeler in Tennessee, the Turpin parents wanted their own reality TV show – a platform they thought could make them famous.

Speaking to The Mirror, Lambert said the couple moved to California from their home in Texas (police say that’s when the abuse “intensified”) in order to be closer to Hollywood. They wanted to make “millions”.

“She used to say how they would be perfect for television and would often mention they would be bigger that the reality show Kate Plus 8,” Lambert said.

It’s reported Louise wanted yet another child to increase the family’s potential as reality TV stars.

“Only last month Louise told me her and David were planning to have another child,” Lambert said.

“I asked her why on earth they wanted more children and she said about wanting a reality TV show.”

“They didn’t care about the kids — it was all about them.”

Louise’s younger sister Teresa Robinette has backed the claim that the parents wanted to keep growing their family.

This insight comes after an unnamed source close to the investigation told reporters police are fearful there were more children who didn’t survive the abuse. Local authorities wish to send cadaver dogs into the home, Crime Watch Daily reports, in an attempt to detect human remains.

The police combed the house for evidence in the days following the children's rescue and the couple's arrest. "The whole house is a crime scene," Riverside Sheriff's Deputy Mike Vasquez told AAP.

Hundreds of journals from the siblings were found, with district attorney Mike Hestrin telling ABC News they could shed additional light upon an investigation that is not done yet.

"We have a lot of evidence to go through. We’ve got the journals to go through, more interviews to do."

David and Louise appeared in court on Thursday. Both pleaded not guilty to 13 counts of torture; one lewd act on a child; seven counts of abuse of a dependent adult; six counts of child abuse; and 12 counts of false imprisonment.

During the press conference on the same day, Hestrin said more charged will be filed if further evidence comes to light.

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