A judge in Texas has dismissed a child sexual assault charge made against a longtime USA Gymnastics athletic trainer and former colleague of disgraced team doctor Larry Nassar.

Debbie Van Horn was initially charged with one count of sexual assault of a child in Walker County -- home of the famed Karolyi Ranch, which was the former training center for the U.S. national team -- in September 2018. Prosecutors requested the charges be dismissed last week due to insufficient evidence.

Van Horn worked side by side with Nassar for years at the Karolyi Ranch and at gymnastics competitions around the world. She was accused by a former district attorney, who has since left the office, of acting as a party to a sexual assault perpetrated by Nassar. Texas law of parties holds a person "criminally responsible as a party to an offense if the offense is committed by his own conduct, by the conduct of another for which he is criminally responsible, or by both.''

However, Walker County District Attorney Will Durham said there was insufficient evidence to take Van Horn to trial.

"Therefore, Debra Van Horn will not be prosecuted as a party to the 2012 offense alleged to have been committed by Nassar,'' he said in a prepared statement.

Durham was not with the district attorney's office when Van Horn was indicted.

Before Nassar was sentenced to up to 175 years in state prison for sexually assaulting his patients and others, he described Van Horn as the "neck" that kept his head on straight. He called her "the single most influential person in the history of sports medicine for the sport of gymnastics."

Van Horn was one of five others who have faced criminal charges related to the fallout from the sprawling Nassar scandal. One of the five, former Michigan State medical school dean William Strampel, is serving a one-year prison sentence. Former Michigan State president Lou Anna Simon and former gymnastics coach Kathie Klages are awaiting trial on charges of lying to police. Former USA Gymnastics president and CEO Steve Penny is awaiting trial on an evidence-tampering charge. Penny's case is also being tried in Walker County, Texas.

Van Horn and her attorney did not respond to requests for comment.

The Associated Press contributed to this report.