A California school bus driver faces criminal charges stemming from accusations that he maintained inappropriate relationships with multiple students over the past decade.

According to KSBW, 58-year-old Bill Harvey is expected to be charged with counts including rape, kidnapping and stalking.

He had been employed by the Salinas Union High School District, Monterey County’s largest, at the time of his arrest earlier this month and has since been placed on leave.

In an announcement this week, authorities alleged Harvey sexually assaulted at least two children who rode on his bus.

He plied at least one student with gifts and met with the minor multiple times off campus, according to police.

The first alleged act happened about eight years ago an involved a 13-year-old victim, according to CBS News. The latest allegation came last year.

Both victims are special-needs students, said Salinas Police Cmdr. John Murray.

“We trust someone like this to take care of our kids,” he said. “That trust was violated, and even worse, these victims may have been groomed for this purpose.”

Harvey pleaded not guilty to the charges against him when he was arraigned earlier this week.

The school district issued a statement expressing its shock over the arrest of its bus driver.

“This is a disturbing set of allegations and we are taking it seriously,” the statement read.

District officials said they are cooperating with police as the investigation moves forward.

“We placed this employee on administrative leave, and as a result, he will have no contact with any Salinas Union High School District student,” officials explained.

[Featured image: Bill Harvey/Monterey County Jail]