(CNN) — A Tennessee couple is under arrest and facing allegations that they imprisoned their 'custodial adopted' children for months.
Investigators say one of the children called 9-11 and told police she and her sister were kept in a locked room while their brother was locked in an un-insulated garage outside.
A Tipton County crime scene van arrived at a Gladney Road mobile home Friday night soon after a judge signed a search warrant.
Detectives spent the evening collecting more evidence in a disturbing child abuse case.
"This has been one of the worst cases," said Chief Deputy Donna Turner.
Will Cater and his wife Wylie Sue are charged with abuse and false imprisonment. Both are accused of forcing three adopted children to live in locked rooms since last Spring.
A 14-year-old boy in an old trailer without heat or running water.
"Eating, bodily functions, going to restroom and all that was having to be in these enclosed rooms," said Turner.
"They were really quiet."
This schoolmate, unidentified at the request of her mother, rode the bus with the three children.
School was the only time investigators say they were allowed to leave their confinement.
"I'm more surprised and shocked than anything, because I never thought they'd do that to their own kids."
One of the kids eventually told someone at school, who contacted the sheriff's office.
"And you've never suspected any of this was going on?"
"It's troubling to know that people would imprison children or confine children in their own home."
We're told the three children are now in foster care as their parents face prosecution.