Janissa had told ABC affiliate KSAT after the incident that she and another student were meeting after school March 29 to discuss comments the other student had purportedly made about Janissa. The 12-year-old told NBC affiliate WOAI that other kids started to congregate in the hall to see whether the two girls planned to fight.
"I was walking toward her, telling her, 'Let's go somewhere else,' because there was a lot of people," Janissa told KSAT. "Then that's when other people came over and the officer thought we were going to fight."
The school district would not release details about the student seen in the video, but Janissa's family has said it was Janissa.
The video, which emerged on YouTube last week, seemed to show Kehm struggling to hold the student from behind as her schoolmates called out, "Janissa! Janissa, chill!"
The officer then hurled the girl to the ground - and a loud crack could be heard as her head slammed against the brick pavement.
The crowd gasped and then fell silent.
"Janissa! Janissa, you OK?" one student said. "She landed on her face!"
The officer handcuffed the girl, pulled her to her feet and escorted her from the area as another student reached out and gently touched her shoulder.
District officials learned about the video when it surfaced on social media.
"The video is very disturbing," district spokeswoman Leslie Price said in a statement to The Washington Post. "We immediately launched a formal investigation, which is being conducted by both district police and administration."
It has drawn intense criticism.
Judith Browne Dianis, co-director for Advancement Project, a civil rights organization, said last week that it "demonstrates the urgent need to take action to remove police officers from our schools."
"It is unconscionable for a 12-year-old student involved in a verbal altercation to be brutalized and dehumanized in this manner," she said in a statement. "Once again, a video captured by a student offers a sobering reminder that we cannot entrust school police officers to intervene in school disciplinary matters that are best suited for trained educators and counselors."
She also questioned whether such incidents are driven by something more.
"How many students of color must be brutalized by police officers in their schools before we recognize the pattern?" she said in the statement. "We saw this with 17-year-old Brittany Overstreet in Tampa, Florida, who was body-slammed and knocked unconscious by a school resource officer; in Baltimore, Maryland, where a middle school student required 10 stitches after she was assaulted by a school resource officer; in Columbia, South Carolina, where a student was thrown across a classroom, handcuffed and arrested for using her phone during class; and now, in San Antonio.
"We cannot wait for another violent video of police brutality in our schools to surface before we take action."
Martinez, the superintendent, told the San Antonio Express-News that the decision to fire Kehm came after district officials decided his use of force was unwarranted. Also, Martinez said, Kehm failed to report it to the district.
"That did not happen," Martinez told the newspaper. "When the police officer did submit a report, it was not at all consistent with the video."
Martinez said Kehm's report suggested the girl had fallen down.
"We recognise the high level of emotion generated by this incident, and we want to ensure the public's trust in this investigation, that it is being conducted without any perception of bias," Martinez said in the statement.
"We know that this incident does not define our district police department, which is dedicated to serving and protecting our school community. We all want to make sure this kind of incident does not occur again, and we will seek to identify areas where improvement may be needed."
