INDIANAPOLIS | A southern Indiana bus driver accused of groping a 17-year-old student four years ago avoided prosecution because he was employed by the bus company, not the school district.

Linda Pence, the Democratic candidate for Indiana attorney general, says the case, which went to the state Supreme Court last year, demonstrates a critical weakness in the state's child seduction law.

The law, which Pence said is often the only avenue for prosecuting sexual advances made toward teens who are at least 16 but not yet 18, applies to parents, guardians and school employees. Pence pitched legislation Thursday to add bus drivers, camp counselors and volunteer coaches to the list of caregivers who could face criminal charges.

"Sixteen to 18-year-old girls and boys are at the most vulnerable stage, often, in their lives," Pence said at a news conference outside the Statehouse. "Anyone in a position of trust and control over a child who betrays that trust should go to jail."

Pence, a private practice attorney in Indianapolis, said she first became aware of the "loophole" while representing a pair of teenage girls allegedly seduced by an Indianapolis-area coach.

The families pursued a civil suit, ending in a settlement, after the coach avoided criminal charges because he was a volunteer, Pence said. She declined to name the parties involved.

Pence, who worked for the U.S. Department of Justice from 1973 to 1984, is running against Republican Greg Zoeller, the chief deputy to outgoing Attorney General Steve Carter.