OAKLAND (CBS SF) — An East Bay mother was demanding answers Wednesday after an Oakland high school security officer was caught on camera tackling her son on campus.

The confrontation happened in the main office at Fremont High School on January 8th. The vice principle and a school security officer were talking to a student.

As the student tried to leave the office, the guard stopped him. Video showed the confrontation that followed.

The clips reveals a lot of pushing and shoving before the guard eventually forced the student to the ground. The confrontation continued for another minute behind a wall.

Security officers later handcuffed the student, identified by his mother as 16-year-old Roberto Canales.

Ana Canales gave KPIX 5 pictures taken in the hospital that showed bruises on Roberto’s face, shoulders, arms and hands.

“[It’s] sad; very sad,” she said.

The mother said the guard punched his son behind that wall.

“It’s hard for me. Because supposedly I need to protect my children,” said Ana Canales.

She gave KPIX 5 Roberto’s medical report, which showed he was under the influence of cocaine at the time of the confrontation. School administrators say because he appeared high, they couldn’t let him leave.

But the mother says the student didn’t threaten anyone and the school administrators could have calmed the situation down.

“The security is very, very hard with my son,” said Canales. “I think so. I see the video. He’s pushing him.”

Misael Sanchez, another Fremont High student, expressed her agreement.

“I don’t think all that force was necessary. They’re grown men, and he’s just a kid,” said Sanchez. “He doesn’t have as much force as they do.”

School District Police Chief Jeff Godown is investigating the incident.

Gowdown was out of town, but told KPIX 5 over the phone that the student refused to stay and the security officer had very few options.

“You end up having a physical confrontation with somebody. Unfortunately, it never looks good,” said Godown. “I can see why people think that the video is problematic. I just ask people not to rush to judgement because they don’t have all the facts.”

Two years ago in the same office, two guards punched and choked a different student. Those guards resigned.

Some students and teachers are upset the district did not suspend the guard in this latest case. They plan to have a community meeting next month to talk about it.