The cell phone video has gone viral on the internet and we're now seeing more of the alleged incident in a second video released by an attorney for Pershaun Goodlow, the alleged victim's mother.
A photo of 16-year-old Lauren Goodlow appears to show injuries to her face - the result of the alleged incident at Dunbar Vocational Career Academy on Tuesday.
"When I first saw the video, I was enraged. And I broke down in tears," said Pershaun Goodlow.
The video released by the attorney shows more of the alleged incident than seen in a previous video.
The man appears to push the student against a wall before the two move closer to the stairs and the student is pushed from behind.
"I couldn't even imagine someone from a school, a staff member, doing that to a child," said Pershaun Goodlow.
"We're not doctors, but she was thrown down a full flight of stairs and tumbled on her back, her neck, her arms, her legs, her head," said Mark Sutter, Goodlow's attorney.
The video then shows the student lying on the ground for several seconds. The man standing over her before a woman appears to check on the girl.
Moments later, the student gets up and moves toward the man, who appears to strike her.
Afterward, another man is seen helping the girl to her feet.
"We as parents send our kids to school to be safe. We send them to be educated. And we expect the schools to be a safe haven," said Sutter.
CPS has suspended the Dunbar security guard with pay as police investigate. ABC7 is not identifying him because no charges have been filed by police.
Goodlow's attorney says the guard arrived at the scene after his client's daughter got in an argument with another student, but denies the 5'4" 10th grader did anything to deserve what's allegedly caught on video.
"She wasn't involved in anything, and certainly any belief that this gentleman had in self-defense would be completely unreasonable," said Sutter.