Kevin Ross, 48, is suspended pending the outcome of the investigation, Vance County Schools administrators said Thursday.
The girl's mother originally told ABC11 that School Resource Officer Warren Durham pushed her daughter into a locker.
"Took her to the emergency room," Roslyn Wynn said. "She has a dislocated shoulder, on her left side. Everything where she was slammed against the locker - all of this is broke. This is like, dislocated. She has a sling on. She has a sprain in her neck."
In a statement sent to ABC11 on Thursday, the sheriff's office said it found "no interaction that rises to levels alleged."
Read the full statement here: "On December 13, 2019, the Vance County Sheriff's Office received a Citizen Compliant concerning an alleged incident on December 12, 2019, between a minor child and SRO Deputy Durham and others, which was separate from the previously reported incident...we have reviewed video for the time before, during and after the time period alleged. Based upon our review of this video, we can find no merit to allegations as provided to us, and further, we can find no interaction that rises to levels alleged."'
A representative speaking on behalf of the girl's family told ABC11 that after reviewing the video, they realized that it was the assistant principal, not the SRO, who slammed the girl into the locker.
"She was so traumatized at the time. It's possible she didn't know which ones was touching her," Wynn told ABC11 on Thursday. "That's why she said both of them. But when I seen it and I told her. She was that more hurt. That it was just the assistant principal."
In a statement sent to ABC11 on Thursday, administrators said: "District officials have met with the family and offered academic support, resources, counseling and other educational setting options to the student. Vance County Schools did suspend the assistant principal in question, pending the outcome of the investigation."
Durham was charged with assault on a child younger than 12 and misdemeanor child abuse in the other case, in which video showed him throwing a sixth-grade student at Vance County Middle School to the ground twice before dragging the student down the hall.
Vance County Sheriff Curtis Brame was "stunned" by the video and asked the North Carolina SBI to investigate.
That boy's family says he still suffers from headaches. He was at Duke Hospital overnight for an MRI but has since been released.
Brame said he plans to interview the Wynn family about their allegations against the assistant principal and then speak with the district attorney.
Surveillance video shows middle school student being slammed, dragged; viewer's discretion is advised: