A former school bus driver and two aides have been charged with abusing a nonverbal child with autism on Long Island.

Investigators say bus surveillance video shows the trio repeatedly tormented a 9-year-old boy with autism while he was being transported to his school, the Masera Learning Center in West Islip. They're accused of bending the boy's toes backward and slapping and kicking him.

Parents of the Longwood Central School District student alerted school officials after their son's behavior changed when he had to get on the bus. They did not want to be identified or speak on camera.

The district sent a statement saying: "Upon learning of these disturbing allegations, the district immediately contacted the Suffolk County Police Department, and we have fully cooperated as they conducted their investigation."

Bus driver James LaGreca, an 81-year-old from Medford, and aides Auga Roberts, 68, of Coram, and Anneris Contreras, 56, of Bay Shore, were arraigned Tuesday. They face multiple counts of endangering the welfare of an incompetent or physically disabled person.

"We were able to identify several instances on several different days in October of 2018 where these three defendants abused this child," says Suffolk District Attorney Tim Sini.

Prosecutors say the driver and aides worked for Medford-based East End Bus Lines and have since been fired.

The defendants are due back in court on March 24. If convicted, they face up to four years in prison for each charge.