The couple accused of imprisoning their 13 children in a Southern California home forced the kids to march through the upstairs rooms of one of their former houses, the New York Post reported Tuesday.

Mike, who lived across the street from David and Louise Turpin and their brood in Murrieta, Calif., told the Post that the family "would march back and forth on the second story at night. The light would be on the whole the time and they would be marching the kids back and forth."

Mike, who declined to give his last name, told the paper that the bizarre occurrence would happen between midnight and 3 a.m.

"I thought they were like a cult," he said, adding that his wife referred to the children as "clones" and noting that they "spoke robotically, in a monotone and at the same time."

In 2014, the Turpin family moved from Murrieta to the nearby town of Perris. On Sunday, Riverside County sheriff's deputies say, one of the children jumped out of a window, called 911 and led authorities to the home where her 12 siblings were being kept.

According to investigators, the Turpin children --ranging in age from two to 29 years old -- were thin and malnourished and some of them were chained to furniture. The 17-year-old girl who escaped was so tiny that deputies initially mistook her for a 10-year-old.

Louise Turpin, 49, and David Turpin, 57, were jailed on $9 million bail. They were scheduled for an initial court appearance on Thursday. Authorities said the pair could face charges of torture and child endangerment.

Riverside County Sheriff's Capt. Greg Fellows told reporters Tuesday that there was no indication any of the children were sexually abused, although that was still being investigated.

Neither sheriff's deputies nor child welfare officials received a single call over the years about the Turpin home. Mike, the Turpins' Murrieta neighbor, told the New York Post that neither he nor his wife saw anything that would have prompted them to call the police.

When the family moved out, Mike said, "there were lots of black garbage bags. I never saw any toys or bicycles."

Kimberly Milligan, a Perris neigbor of the Turpins, told the Associated Press the developer who built the tract where they lived told her the family had a dozen kids when they moved in, although she never saw that many.

The Turpin home in Perris, Calif. (Google)

She described the family as "standoffish" hoarders who had their garage filled with books and who often let the grass in their front yard grow out of control, unlike other families on the block.

"I got an impression, that, you know, 'You stay in your lane, I'll stay in my lane," she said. "It was never, 'Hi.' Never a wave. Nothing."

Her 26-year-old son, Robert Perkins, said he only remembers seeing four children outside the home, recalling they all appeared pale and skinny, as if they never ventured outside.

The Associated Press contributed to this report.