The video shows one of those inmates, a mentally ill man emerging after nine straight months of solitary confinement -- no longer able to speak a language anyone could understand.
"The man's hair, his beard was matted up," said Patrick Perry, the correctional officer who blew the whistle. "I had never seen an inmate live in those kinds of conditions."
Originally convicted on drug charges, Frank Horton failed to check in with his parole officer. That's how he ended up at the CCA facility in December 2005.
Horton's mother couldn't believe her ears when she heard about her son's condition. "They could be talking about someone else, not my son," Cytherea Braswell said.
His grandmother was equally shocked. "We never heard nothing else other than 'Well, he's in there and he's doing OK,'" said Mary Braswell.
But one video clip -- a month after his arrival -- shows the first signs of trouble. After a fight with a then-cellmate, CCA reports show that the cellmate told officers that Horton was "hearing voices" and believed people were "trying to kill him."
"An actual CCA intake form noted that Mr. Horton had had a history of psychological and mental illness and probable schizophrenia was noted on those forms," said the family's attorney, John Ray Clemmons of the law firm Blackburn & McCune.
So guards locked him up in solitary, and Horton became more and more difficult to control. Finally, as another video clip shows, he began to refuse to leave his cell at all.
Clemmons said, "Instead of treating Mr. Horton for the illness which was causing him to act in this manner, they punished him. They sprayed him with chemical agents. They put him in solitary and segregated confinement for extended periods of time with no medical treatment."
Video clips -- obtained by NewsChannel 5 Investigates -- show Horton repeatedly being sprayed with inflammatory chemical agents.
Then, in May 2007, they stopped trying to force him out.
"Frank Horton went from being a beast to being, you know, barely able to speak to me," the former correctional officer, Patrick Perry, testified in a videotaped court deposition.
Perry was CCA's overnight supervisor at the facility. He says the inmate spiraled downward, as the days in his darkened, filthy cell turned into months.
Still, prison officials refused to forcibly remove him. Perry claimed it was because they feared too many incidents involving force could jeopardize their yearly bonuses.
"They would go to Frank's door, look in on Frank, [ask] 'Frank, you all right?' As long as he was living and breathing in that cell, they kept moving."
Horton's grandmother, Mary Braswell, added, "I would call every so often and talk to the counselor. And she always said, 'Well he's doing OK.'"
She said that Horton's family kept being told he had not authorized them to visit him.
Then, one night, Perry stopped by Horton's cell. "I tried to converse with him, and he was speaking gibberish to me. And, at that time, that's when I made up my mind to go the Health Department."
Finally, Horton was brought out of solitary -- after health officials intervened and after the family, who'd gotten wind of the situation, hired an attorney to go see him.
Clemmons recalled, "Mr. Horton was walking in circles around the cell, completely nude with nothing but what I would call an old barn quilt, just a thick blanket draped over him."
CCA officials refused to answer questions about exactly what happened.
But get this: after Perry went outside the company to get help for Horton, CCA suspended him -- eventually giving him a choice to accept a transfer or resign.
Perry resigned, and CCA paid him a severance to keep quiet.
"Frank's situation was the tip of the iceberg," Perry said, under oath. He explained that there were also other mentally ill inmates who, like Horton, were neglected.
Still, prison bosses pressured guards to keep secrets from the government monitor assigned to the facility. "Yeah, I made a mistake of talking to [Davidson County Sheriff's Department monitor] Jimmy Hale one time about something. I got my ass chewed for it royally," Perry added.
Mary Braswell echoed, "To me -- they didn't want anybody in there to see."
And Frank Horton's family said they believe there's a good reason CCA didn't want anyone to see what become of their loved one.
"They was treating him worse than an animal because if it was an animal somebody would have went to his rescue," Braswell said.
CCA has replaced the warden at that facility. But a spokesperson said that, because the company faces a lawsuit, they can't comment on whether they think what happened to this inmate was right or wrong.
Horton's lawyer got a court order to have him moved to a state prison hospital. He's now on medication and, the family said, showing signs of recovery.