SAN ANTONIO -- A 12-year-old girl was suspended from school following an altercation with another student that ended with a police officer body-slamming the girl to the ground, her mother said.

Gloria Valdez told CBS affiliate KENS her daughter, a student at Rhodes Middle School, suffered swelling to her temple after being thrown to the floor by the school district officer.

Cellphone video shows a uniformed officer struggling with a girl, then slamming her to the ground. The officer appears to handcuff the girl before having her stand and leading her away.

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Valdez told KENS the officer's actions were uncalled for.

"Supposedly he was threatened by her, that she kicked him, but in the video her legs never went up," Valdez said.

Valdez's daughter did not want to go on camera but told KENS that she was having a conversation with another girl when a crowd surrounded them. She said that's when the officer put his hands on her.

"All he had to is grab her and put her to the side," Valdez said.

Valdez acknowledged to the San Antonio Express-News that her daughter has fought with others before but said another student started the March 29 altercation.

"She had been bullied at the beginning of the school year," Valdez told the newspaper. "I talked to a counselor, the vice principal and principal, and they said they'd look into it. Finally, the other student started attacking her and got into a fight, and it led to my daughter getting suspended (for three days)."

A spokeswoman for the San Antonio Independent School District said the officer has been placed on paid leave.