JACKSONVILLE, Fla. -- A former teacher pleaded guilty Monday to charges that he had sexual contact with a 16-year-old student.

William Tinsley IV was a math teacher at Lighthouse Christian School when he was arrested in April 2008 and charged with custodial sexual battery -- a first-degree felony.

Tinsley says it was consensual -- but investigators say he used his position of power over the student to initiate sexual activity.

Tinsley was suspended after his arrest and later fired from his job.

In court Monday morning, Tinsley pleaded guilty to child neglect, a third-degree felony.

Prosecutors said the sexual activity happened when the student came to Tinsley's Arlington home in October 2007. Lawyers said that because of legal difficulties prosecuting the custodial issue, the state agreed to the plea agreement to the lesser charges.

"We had a significant legal issue in this case with proving that the defendant was in a position of custodial authority over the victim when the incident took place at his house after school hours," said Assistant State Attorney Alan Mizrahi.

Prior to working for Lighthouse, Tinsley worked with the Duval County School District, and Duval administrators have said he was fired over "similar accusations," but his teaching license was not suspended.

"Unfortunately, this is not your first time manipulating young girls' minds, but hopefully it will be your last," the victim's father told Tinsley in court. "We are angry because you stole our daughter's senior in high school memories. You were the role model, the mentor, the teacher."

Tinsley was sentenced to two years probation. As part of Tinsley's sentence, he will never be able to teach or coach children again.