A 17-year-old student is in custody after threatening to open fire on his California high school, even though he said his comments were a joke.
Authorities say a security guard at El Camino High School overheard the student's threat last week.
The teen confirmed the comments and the Los Angeles County Sheriff's department took action.
He was said to be angry about a teacher's issue with headphones in class.
A search of the student's home turned up multiple weapons.
The teen's 28-year-old brother was also arrested on a variety of weapons charges.
The sheriff said that the number of school threats has increased since the attack in Parkland, Florida.