WHITTIER, Calif. -- Authorities say they've thwarted a student's plot for a mass shooting at a Southern California high school. The Los Angeles County Sheriff's Department said Tuesday that a security guard at El Camino High School in Whittier overhead a "disgruntled student" threaten to open fire on the school on Friday, just two days after 17 people were gunned down at a Florida high school.

Sheriff's spokeswoman Nicole Nishida told The Associated Press deputies discovered "multiple guns and ammunition" after searching the student's home.

The suspect is a 17-year-old boy, according to the Whittier Daily News. A spokesperson for the Norwalk-La Mirada Unified School District told the publication the boy threatened to go home and bring back a gun following a disagreement with a teacher over his headphones, which are not allowed during class.

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It was unclear if the suspect has been arrested, or who purchased or owns the weapons, CBS Los Angeles reports.

Officials scheduled a news conference for Wednesday.