The parents of a 10-year-old boy with Down syndrome says abuse suffered at the hands of a teacher’s aid at a Temecula elementary school has reversed developmental progress and left him dealing with post-traumatic stress disorder.

Hudson Peterson was developing well until age 7, when he attended first grade at Tony Tobin Elementary School in Temecula, according to his parents, Shannon and Scott Peterson.

Hudson then began coming home with bruises, they said. An investigation determined a teacher’s aide who had been working with Hudson had been abusing him, including picking him up by his wrist, yelling at him and hitting him, they told KTLA.

The emotional and physical abuse caused Hudson to have behavioral meltdowns, revert to becoming nonverbal and require diapers, his mother said. He’s being treated for post-traumatic stress disorder.

The family has filed a lawsuit against the school, and jury selection is scheduled to begin Friday.

The parents say they’re further upset because despite confirming the abuse through an investigation, the school asked the aide – whom the Petersons identified as Debbie Woodard – to resign, rather than terminating her. That decision allowed her to maintain a clean disciplinary record and continue working with students at other schools, the Petersons said.

Temecula Valley Unified School District representatives said the district declined to comment on pending litigation.