A security officer on Friday heard the teen "say that he was going to shoot up the school sometime in the next three weeks," Los Angeles County Sheriff Jim McDonnell said at a news conference.
The school reported the teen, and deputies found an assault rifle at the home registered to his 28-year-old Army veteran brother and another that was not registered, which is a felony in California, McDonnell said.
Notice - it was a security guard who overheard it!
Full story found @ California school shooting plot foiled, assault rifles found