The teacher in southern Sweden had asked the girl to stay behind after class, only to make inappropriate comments and touch her. The girl told her boyfriend about the incident, but when he suggested that she go to the police and report the teacher she decided it would be too difficult to prove what had occurred.
The regional Sydsvenskan newspaper on Friday reported that rather than face a word-against-word situation, with no guarantee that a police report lead to prosecution, she instead decided to tape the man, who has been working as a teacher for more than three decades.
She asked the teacher to meet her in a parking garage, where she then recorded his advances for nineteen minutes.
In the district court, the school psychologists and two principals said they recognized the teacher's voice. He, meanwhile, said that while he admitted it was his voice on tape, he believed his words had been doctored.
That claim was refuted by the police crime lab (Statens kriminaltekniska laboratorium - SKL) after an analysis.
The Malmö district court has now found him guilty of sexual harassment and given him a suspended sentence. The man, who has been suspended from the school where he worked since the incident was reported, now risks losing his job, Sydsvenskan reported.
He must pay 20,000 kronor ($3,100) in damages to the girl.