The incident happened at about 3:45 a.m. Wednesday at Spurgeon Intermediate School on the 2700 block of West Fifth Street.
Surveillance photos caught the three burglars in the act. Police said two of the three got away, stealing 25 computers.
One suspect, identified as 20-year-old Jaime Fernandez of Palmdale, was taken into custody.
He is being treated for injuries from a police dog during the arrest.
If you have any information regarding this incident, you're urged to call the Santa Ana School Police Department at (714) 558-5535.