CHICAGO — A Chicago police officer is under investigation after allegedly shoving an eighth grader at a South Side school.

According to the child’s mother, the incident happened before the first bell rang outside of Gresham School of Excellence in the City’s Auburn Gresham neighborhood back in May, and was caught on the school’s security cameras.

The security footage shows eighth grader Jaquwuan Williams walking into school with a black sweatshirt and jeans on, having just wrapped up a game of basketball with his friends before heading in to get ready for school.

Video shows as he approaches his teacher, the man standing next to her, an off-duty Chicago police officer, turns to him and shoves him by the neck.

“The casual violence, the completely unprovoked attack would be shocking if it was anyone,” said Jordan Marsh, the victim’s attorney. “There’s no question about it. This was a battery and the fact that it was on public property makes it an aggravated battery.”

Marsh said he wants to hold the officer accountable for his actions, but it’s also left him with a lot of questions.

“You think about the confusion the profound confusion when you’re in those formative years,” Marsh said. “In the middle of that, to throw in an unprovoked assault by an off-duty police officer, you wonder how it’s going to affect him the rest of his life.”

The entire video clip is about 30 minutes long and never shows the teen interacting with the officer before the assault.

When asked about the incident, the officer’s attorney, Tim Grace, said, “He acted in a manner to protect the children and staff from a student who clearly was a threat to all present. He was acting within the scope of his duties as a law enforcement officer.”

Marsh countered, saying there is no evidence Williams posed a threat to anyone — and while the incident lasted less than 30 seconds — it left a lasting impression on him.

“Now their idea of what a police officer is and does is forever altered,” Marsh said. “If they ever ever want the trust of the community this has to stop.”

According to Marsh, he expects criminal charges to be filed, while the Civilian Office of Police Accountability (COPA), CPD Internal Affairs and the Cook County State’s Attorney’s Office continue their investigations.