The investigation continues into two Darlington County School District employees charged for hitting a special needs child.
Darlington police released the video to NewsChannel 15.
It shows a teacher's aid and behavioral manager at Saint John's Elementary School slapping a 10-year-old special needs student.
Rosanna Dudley and Tomeka Self are charged with simple assault and battery. They're on administrative leave without pay from the district.
The district says it has video cameras on 100 of 104 buses.
Officials say the cameras run while the buses are running the routes, including when the buses are stopped to load or unload children, estimating five hours of run time a day .
That amounts to approximately 400 hours of video generated a day by the bus fleet, far more than the district says it can reasonable review on a regular basis.
The district says the video it gets every day is used for training purposes, to spot check, for investigations, and for backup.
They say school bus drivers, teachers, school administrators and district transportation employees work closely together, communicating frequently about bus and transportation issues.
Officials say usually it is the bus driver who alerts them to problems or discipline issues. Sometimes it's the parents or the students themselves that make them aware of concerns.
"They let us know if there's concerns. If there's good things that are going on and if there's issues that need to be looked into. Then those videos are pulled so that then we can investigate and get more information so that we can address quickly any problems that arise," said Audrey Childers, Darlington County School District Spokeswoman.
At least every two weeks, Childers says the district spot checks all the bus video cameras to make sure they are working and to deal with maintenance issues that arise.