BROWARD COUNTY, Fla. -- A third student has come forward and has accused a Crystal Lake Middle School geography teacher of sexually assaulting him.

Thursday, Adrian Valdez, 29, was charged with additional counts of sexual battery, exposure of sexual organs and lewd and lascivious molestation for an alleged assault on Aug. 28, when Valdez drove one of his 14-year-old students to his house.

Broward Sheriff's Office Sex Crimes detectives first arrested Valdez on Oct. 21 for an alleged assault upon a 12-year-old boy. Last month, publicity from that arrest prompted a 14-year-old boy to tell investigators that he too was victimized by Valdez.

Investigators said each of the alleged assaults on the boys was strikingly similar. According to detectives, in each case, Valdez offered his students rides home then took them to his house, showed them pornographic videotapes, led them into his bedroom and committed identical sex acts in the same location within the room.

In addition, authorities in Orangeburg, S.C. have reopened an investigation into allegations that Valdez victimized a 16-year-old boy that he had been mentoring in 2002.

Valdez is still being held without bond.

Anyone with additional information about Valdez is asked to call detectives at (954) 321-4240.