From an article:
Stockton Unified Police Chief Jim West said one round fired from the 22-caliber semi-automatic handgun into the floor of the classroom as one boy was passing it to the other at around 9 a.m.
Both students were subsequently arrested and the gun was secured by officials, said West.
Neither boy cooperated with officers and both refused to answer any questions, said West.
No injuries were reported in the incident and school was scheduled to continue as usual for the day, West said.
According to West, parents of children at the school were all notified of the incident.
The article didn't say where they got the gun.
Every gun in the hands of a child must first pass through the hands of an adult.