SANTA ROSA, Calif.—A Petaluma man in jail for allegedly molesting a 13-year-old boy drove school buses for four years in Santa Rosa.

The suspect, 60-year-old Richard "Butch" Guillen, drove a regular daily route for Santa Rosa schools since April 2006 as an employee of Laidlaw, a national bus company bought by First Student Inc. in 2007.

Maureen Richmond, a spokeswoman for the bus company, said Guillen had passed criminal background checks and had a clean driving record.

Guillen was arraigned Monday in Sacramento Superior Court on charges he molested a 13-year-old Santa Rosa boy entrusted in his care on an overnight trip.