For years, the 13 Turpin siblings were kept prisoner in their Perris, California, home

In the early morning hours of Jan. 2018, two of the Turpin siblings decided to flee their suburban Perris, Calif. house. One went first, out a bedroom window. Before she left, she faked a lump in her bed to make it look like she was still sleeping there. Her sister left two minutes later, from the same window, while two of her shackled siblings looked on.

One sister got lost and returned to the house, but the other called 911 — bringing the police and ultimately freedom. Their parents, David and Louise Turpin, pleaded guilty in 2019 to multiple felony counts including torture and false imprisonment and are now serving a sentence of 25 years to life.

It was a dire warning to their kids that set the abused children's escape plan into motion, authorities say.

"David and Louise agreed that they were just going to chain all the kids up once they got to the new house in Oklahoma and they were about to move in the next few days," Riverside County Deputy District Attorney Kevin Beecham tells PEOPLE. "That was what pretty much lit that fuse."

David and Louise Turpin
| Credit: Jae C. Hong/AP (2)

Beecham, who worked closely with the siblings and saw them twice a month when he was preparing a case against their parents, says at least five of the kids knew about the the early-morning escape plan — and it wasn't their first plot to flee.

"They knew that there's this place called Vegas, and it was one of the happy times that they had in their lives, so they're like, 'We need to get to Vegas,'" Beecham recalls. "That was just ingrained in their head."

F:PHOTOMediaFactory ActionsRequests DropBox48673#Courtesy Billy Lambert1.jpg
The Turpin family
| Credit: Courtesy Billy Lambert

For more on how the Turpin children are taking back their lives, subscribe now to PEOPLE or pick up this week's issue, on newsstands Friday.

Beecham says one of the daughters called a taxi company and asked how much it would cost to take a taxi to Las Vegas.

"They called this taxi cab company and they're like, 'Okay, where do you want to go?' They're like, 'We want to go to Vegas.' 'Okay, where are you? 'We're in Perris.' 'Okay, but where in Perris and where in Vegas do you want to go?' And that's kind of where it stopped," he says. "They didn't trust anybody. They were afraid that whoever they called would just bring it right back to the parents, and then they would just get chained up for the rest of their life."

Some of the siblings, says Beecham, chronicled their abuse.

"My investigator went through hours, just hundreds of hours, of video surveillance footage, as well as camera footage that these kids would try to sneak," he says. "They would sneak taking pictures of the chains on their siblings."

Police Arrest Parents After Escaped Child Calls 911 On Parents Who Kept 13 Siblings Restrained In Shackles
The Turpin’s Perris home
| Credit: Sandy Huffaker/Getty

Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Beecham says Louise initially didn't seem to understand that what she did was wrong.

"She wrote an apology letter basically saying, 'Sorry I chained you up. It won't happen again. I'll be a better mother.' She was just very naïve to the whole thing," he says. "She was just thinking that she needed parenting classes and that would be the end of it. David, not so much. I think he knew the writing was on the wall early on."

If you suspect child abuse, call the Childhelp National Child Abuse Hotline at 1-800-4-A-Child or 1-800-422-4453, or go to All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.