Student threatens to 'shoot up' his school — what police find at his home is chilling

California law enforcement authorities say they might have prevented a school shooting at El Camino High School after a student muttered that he was going to "shoot up" the campus.

Here's what police discovered at his home

Here's what happened

Police were called immediately after a 17-year-old student said that he was planning to "shoot up" the school and was overheard by a safety officer. During an investigation, they discovered a cache of weapons at his home.

Robert Jacobsen, the general counsel for the Norwalk-La Mirada Unified School District, said that the student made the comments after a disagreement with a teacher over headphones.

Marino Chavez, the safety officer, questioned the student about what he overheard him saying. After investigating the matter, the student said that he was simply joking.

“He did say that he was just kidding, he did not mean it. I said, ‘Well you can’t say those things on a school campus,'" Chavez said.

Chavez informed the police, who saw that an AR-15 was registered at the student's address. When they investigated the home, they discovered several weapons, including two AR-15 rifles, two handguns and 90 high-capacity magazines.

The student's older brother is an Army veteran and said the weapons were his, but he was arrested and charged with several counts including "possession of an assault weapon, import of high-capacity magazines, and failure to register a personal handgun.

The student was also arrested for the threats he made.