Oakland High School released disturbing video capturing the moments where a freshman with cerebral palsy, handcuffed to a wheelchair, was brutally beaten by a security guard. This student's offense? Moving too slowly to class. Marchell Mitchell, 23, was fired and charged with child abuse for cuffing, punching and dumping Francisco Martinez, 17, out of his wheelchair on Monday May 19.

The Chronicle has more:

Mitchell ordered the student to move toward his next class, but the student "either refused to comply or was slow to do so," Principal Matin Abdel-Qawi wrote in a letter to parents.

Mitchell then took the handles of Martinez's wheelchair and pushed him toward class, prompting Martinez to object and try to slap away the guard's hands, officials said. Mitchell then handcuffed Martinez and continued to roll him, and the student turned around in his wheelchair and spat in Mitchell's face, authorities said.

"The security officer then struck the student several times before dumping him from his wheelchair onto the floor, at which time another security officer intervened to restrain his partner," Abdel-Qawi wrote.

Martinez was admitted to Children's Hospital on Thursday to be treated for non-life-threatening injuries. "He slapped me. He hit me so hard, it threw me out of my chair. I hit the floor with my chin first. I had a scar right here," Martinez told KTVU Thursday night. Martinez also claims that, though not seen in the video, the guard beat and threw him to the ground in the elevator ride beforehand, telling him, "I hope you don't walk for another two or three weeks."

When asked to explain why he spat at the officer, Martinez said, "I was handcuffed. I had no way to defend myself except for my mouth."

Mitchell, who was hired by the school district after an "extensive background check," will appear in court on June 16th for a pretrial hearing.