15-year-old Elizabeth Thomas of Tennessee was found April 20 isolated in a hut in rural California, 2,500 miles away from her home, after being kidnapped by former teacher Tad Cummins, 50, on March 13.

Authorities claim that Kimberly Thomas, Elizabeth’s mother, 48, physically abused several of her ten children, including Elizabeth, for about a year, beginning in Nov. 2014. Thomas is accused of banging Elizabeth’s head on a washer, throwing her down basement steps and locking her inside.

Documents also say Kimberly hit her children until they bled, knocked one child unconscious with a wooden board and threw a chair at another daughter, bruising her leg. The mother also smacked a child in the head for injecting herself with her brother’s EpiPen, documents say.

The children wrote letters to the Department of Children’s Services about their mother’s abuse before she was arrested, according to a close relative. Anthony Thomas, Elizabeth’s father, was living at home during the period of abuse but separated in Nov. 2015, citing the alleged abuse as reason for the divorce, and taking sole custody of the children.

Anthony Thomas claimed  Elizabeth was vulnerable to Cummins due to the abuse she faced from her mother, according to his divorce documents which stated that Kimberly Thomas engaged in a year-long campaign of abuse against the girl. He claimed the mother’s abuse towards the teenager left her open to ‘grooming.’  Anthony said Cummins brainwashed his daughter, and used his position of authority to ‘prey upon her, groom her, and ultimately entice her into running away with him.’

Director of the Crimes Against Children Research Center at the University of New Hampshire, David Finkelhor, told DailyMail.com that a history of abuse at home can make children easily influenced to manipulation disguised as help.

‘They’re very vulnerable to the grooming because this is an adult who seems to care about them and is interested in them, and that’s probably something they’re not getting elsewhere,” he said.

Danielle Thomas, Elizabeth’s sister-in-law, claimed that Cummins knew Elizabeth had been abused and used that information to his advantage. After returning home, Danielle told reporters Elizabeth has been seen ‘curled up in the middle of the floor crying and shaking and having panic attacks’ since she returned home.

‘We have a 15-year-old girl with a 50-year-old man and he obviously used his power, his authority to, whether it’s to groom her or convince her, to do certain things,” she said. Cummins described Elizabeth as ‘a really good friend’ and told school officials that she would leave her other classes during the school day to come see him ‘when she needed someone to calm her down.’ Cummins was told on April 24 that he would return to Tennessee to stand trial, facing a minimum mandatory prison sentence of ten years on federal charges