James Noel, 45, this week admitted he paid money to shock the 25-year-old with an electrical device, even though she complained that it was painful.
The 45-year-old pleaded guilty Monday in U.S. District Court in Kansas City to one count of conspiracy to commit sex trafficking by force, fraud or coercion.
As part of the plea, Noel agreed to cooperate with the government and testify in court against four other men facing federal charges in the case.
The alleged "mastermind" of the operation, Edward "Master Ed" Bagley, is accused of branding, torturing and sexually abusing the mentally disabled woman over a period of five years at a Lebanon, MO, trailer home.
The indictment against him alleges that he met the woman when she was a 16-year-old runaway and persuaded her to move into his trailer with promises of a "great life" and a future as a model and dancer.
Instead he began giving her drugs, showing her pornography and sexually abusing her.
Then when she turned 18, he persuaded her to sign a 'sex slave contract," which he said bound her to him for life.
He then "beat, whipped, flogged, suffocated, choked, electrocuted, caned, skewered, drowned, mutilated, hung and caged" the girl "to coerce her to become a 'sex slave,'" the indictment says.
He also tied her up and hung her in the air, locked her in a dog cage and used staples, nails and a sewing needle and thread during torture sessions.
Six-years ago he began to boast online that the girl was his slave and could be tortured during online sessions or in person.
So Noel gave Bagley cash, cigarettes, computer equipment, sadomasochism videos, coats and meat in exchange for access to the girl, the indictment says.
If she cried out or tried to stop the torture, it only got worse, prosecutors said. Bagley threatened her by claiming to have buried other bodies behind his trailer home and shooting animals that she cared for in front of her, prosecutors said.
Charges are also pending against Dennis Henry, 50 and Michael Stokes, 62 according to St. Louis Today.
As part of the plea, Noel agreed to cooperate with the government and testify in court.
Noel admitted that he shocked the woman using an electrical device, even though she had complained that it was painful.
Noel's attorney and federal prosecutors declined to comment after the hearing.