A former Dallas gymnastics coach manipulated and groomed his 14-year-old student so that he could gain her trust and sexually assault her, state prosecutors argued Monday on the first day of the man's criminal trial.

Christopher Wagoner, 33, faces two felony counts of sexually assaulting the girl over several years at the World Olympic Gymnastics Academy - the same school that produced Olympic gold medalist Carly Patterson and U.S. champion Nastia Liukin.

The girl's mother testified that she began entrusting her daughter to Mr. Wagoner and other coaches after the mother's sister died, forcing her to travel out of state and take care of her niece.

He eventually started giving her private lessons and offered to reduce the $50-per-hour rate if the family would occasionally cook him dinner, including his favorite meal, chicken fried steak, said the mother, who is not being named because it might identify her daughter.

As dinner was being prepared, Mr. Wagoner would work with the girl and provide massage therapy for the back pain she suffered from a gymnastics injury.

"He offered to massage all of that because a physical therapist was so much for us to pay," the mother said. "Mr. Wagoner had informed us that he had been in the [military] service and ... that he'd had training."

The mother said she broke into her daughter's e-mail and found a message from her daughter to Mr. Wagoner saying that something was out of control and that she was vomiting.

A lawsuit filed this month by the girl, who is now 18, contends that Mr. Wagoner suggested that she consider purging techniques use by bulimics to maintain her weight. After the eating disorder made her ill, he recommended she use cocaine, the lawsuit alleges.

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