As an independent charter, Ánimo Mae Jemison does not have a Los Angeles School Police presence, Sheriff's Department spokesman Rudy Perez said. The school in question has not been named by sheriff's officials. He did not identify the student, say when the arrest or threat were made, and did not name the school.
"The fact that people stepped forward" and reported what they heard allowed authorities to "prevent a possible tragedy today", said the sheriff.
Multiple students overheard the alleged threats and alerted teachers.
Investigators were trying to determine who owns the gun that authorities initially called a ghost gun - a weapon without a serial number made from parts from other guns. In a previous tweet, Sheriff Tim Murakami referred to the capture of a "ghost gun", but Villanueva clarified that the weapon in the threat case has a serial number.
Sheriff Alex Villanueva plans a news conference to release more details.
During a search of the suspect's home, deputies seized an AR-15 assault-type rifle, about 100 rounds of ammunition, a hand-drawn map of the school and a list of names of students and staff members, said Sgt. Robert Dean. The boy was arrested without incident in his home on suspicion of criminal threats, the sheriff said.
In a separate case, a boy at another school was taken into custody involving a planned shooting. The shooting earlier this month at Saugus High School was the first fatal shooting on a campus since the school year began. Bob Boese said. The man, who was not recognized, was held on $35,000 bail, he said.
Deputies conducted an interview with a male juvenile who admitted to posting the photos, writing threatening quotes and posting additional threats online, the statement said. Police say they haven't uncovered a motive for the shooting, which took place on Berhow's 16th birthday. Nathaniel Tennosuke Berhow pulled the.45-caliber semi-automatic pistol from his backpack on November 14, his birthday, and shot students at Saugus High School in Los Angeles seemingly at random before turning the gun on himself.