Roach was released on $30,000 bond Saturday. He could not be reached for comment Monday.

Authorities have not released the accuser's identity.

The girl told sheriff's detectives Roach fondlec her in his classroom during second period and lunch three or four times a week starting in February 2006.

Shortly before the girl turned 15 later that spring, their encounters became more intense, she said. She told detectives she brought a condom to Roach's classroom and they had sex in the closet.

It happened again April 21, the day eighth-graders went on a field trip to Busch Gardens in Tampa, the report states. That morning she met Roach in his classroom and they had sex, according to the report.

The girl, now a 15-year-old high school student, came forward last week, sheriff's office spokesman Jim Leljedal said.

While cases like these may be infrequent, they have grabbed many headlines in recent years, Leljedal said.

''It's uncommon, but it does occur on occasion,'' he said. ``Today these crimes are being reported and we're taking action on them.''

In January 2006, Alex Anninos, a 30-year-old marketing teacher at Cypress Bay High in Weston, resigned after he was accused of having sex with a 17-year-old student at the school. The teenager, who was not one of his students, said it was a consensual relationship and refused to cooperate with authorities. The State Attorney's Office declined to prosecute.

Joe Melita, the Broward school district's chief investigator, said such incidents, though rare, are more likely to happen in high school.

''I'm not sure it's happened much at the middle school level,'' Melita said. Besides criminal charges, the school district can fire teachers who have had questionable contact with students and move to have their teaching certificates revoked.

''The kids are vulnerable. They establish certain ties with people,'' Melita said. ``Then they're being taken advantage of.''

Miami Herald staff writer Hannah Sampson contributed to this report.