Two male students, ages 15 and 16, were arrested as a result of the gun going off in the bathroom.
"We don't have any indication that the weapon was brought with the specific intent to cause harm to anybody," Principal Pasquale Scuderi said.
The shot did not actually harm anyone but the walls of the portable building where the incident occurred are thin. Class was underway right on the other side of the wall. A school employee was nearby.
So far every single month this year there has been a gun recovered on Berkeley High's campus. In fact, while police were on campus investigating Tuesday morning's shot they got a tip.
"There was a student who came forward, an anonymous tipster, who said, 'By the way, I heard there was another student who may have a gun in his backpack,'" Berkeley Police Sgt. Mary Kusmiss said.
It proved true. Another 15-year-old boy was arrested.
"This may be uncomfortable for some of the viewers to hear, but we're quite certain there are weapons in schools everyday that we're not aware of," Kusmiss said.
Investigators are working to find out how the boys got the semi-automatic pistols. They all face a year expulsion and felony charges.
School officials are working to set up a hotline where students can anonymously report tips about guns on campus.
"The fact that we are a high performing school with a lot of high performing kids, makes it seem out of place here, what we are taking from this is guns on campus are everybody's problem, nobody's immune," Scuderi said.