Mark Berndt, the veteran Los Angeles elementary school teacher recently charged with committing lewd acts on 23 children, was previously investigating for groping a student in 1994, but no charges were filed in that case.
Berndt was arrested earlier this week after an investigation triggered when photo lab technicians noticed disturbing images on film he'd dropped off for development and notified police.
A Los Angeles County Sheriff's investigator says the 1994 case was dropped after the district attorney's office rejected the case.
Berndt is accused of taking bizarre bondage photos of students in his classroom and other horrifying acts.
He remains in jail on $23 million bail.