FALL RIVER, Mass. – Massachusetts mother Nicole Brennan said her son’s experience at school last week is causing “horrible flashbacks” and ongoing trauma that’s frozen the boy with fear.

“He has horrible flashbacks,” Brennan told Fox 25. “He clenches all up, just builds up and cries. He is just so sad.”

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The 12-year-old special needs student was allegedly strangled by former Talbot Innovation Middle School substitute teacher Stefan Michaud in front of his classmates last Tuesday. Michaud, 62, now faces charges of strangulation and assault and battery with a dangerous weapon, MassLive.com reports.

School officials immediately terminated Michaud’s employment, and he’s scheduled to be formally arraigned on the criminal charges next week.

“My son had marks all over his neck,” Brennan told Fox 25. “You could see where he was choked. He had broken blood vessels.”

Fall River police contend a school resource officer was called to a special needs classroom at the middle school around 12:30 p.m. March 8, and was met by students screaming for help in the hallway. When the officer reached the classroom she found Michaud straddling the student’s chest on the floor with his hands around the boy’s neck, WCVB reports.

“Officer (Kelly) Furtado intervened immediately, and was able to separate the teacher from the student,” Fall River Police spokesman Lt. Ron Furtado told The Herald News. “Officer Furtado observed red marks to the area where she had observed the teacher’s grasp. The student was immediately take to the school nurse’s office for evaluation.”

Police did not release Michaud’s name because he has not been arraigned, Furtado said, but WPRI published his identity based on police records.

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Brennan told Fox 25 Michaud “picked my son up off the floor, slammed him to the cement, hits his head off the floor, and told him if he fights him back, he will punch him in the face.” She said her son was playing with another student before the incident, but the teacher didn’t like what they were doing.

“Police said the initial reports indicated the altercation was between the teacher and another student at first,” WPRI reports. “When a second student intervened, he was taken down to the floor, where he hit his head and was choked, according to police.”

Talbot officials immediately contacted police and Department of Children and Families following the incident.

Fall River Schools Executive Director of Human Resources Jocelyn LeMaire told WPRI Michaud was classified as a “substitute paraprofessional” and had worked in the district since 2013. She said substitutes are paid on a per diem basis, and must pass a criminal record and fingerprint background check.

Michaud, who was fired following the alleged attack, had no prior complaints or similar issues before the March 8 incident, she said.

Brennan told the Herald News school officials apologized for the altercation, but “no sorries can really take the pain away.”