Police say in a statement that the man was standing with three friends Sunday afternoon near the handball courts on the mostly empty campus of O.A. Peters Elementary School in Garden Grove when three suspected gang members walked up.
Police say there was a brief confrontation before one of the men pulled out a gun and shot the victim twice.
The injured man was in critical condition at University of California, Irvine Medical Center on Monday morning in critical condition with wounds to his back and neck.
No arrests have been made.