A 16-year-old boy was arrested after police received a tip that he had allegedly been recruiting other students to join in on a "mass shooting and/or bombing."
Police in Berkeley, California, arrested the boy on Monday. On Wednesday, police told reporters that they found parts of explosives, assault rifles, knives and other items that could have been used in weapons during a search of the teen's home.
CNN reports that the teen was arrested and charged with threatening to commit a crime which will result in death or great bodily injury and of possessing destructive device materials. The 16-year-old turned himself into the police.
Law enforcement reportedly has arranged for a mental health team to evaluate the teen.
Due to the boy being a minor, police have not released his name. His alleged target was Berkeley High School, though it's unclear if he attended that school.
Brent Stephens, the district's superintendent, sent parents a letter Wednesday explaining the situation and thanking the tipster.
"Speaking up in this instance allowed for the police to intervene in advance of any harm occurring," Mr Stephens wrote.
The arrest comes on the heels of the Uvalde, Texas school shooting at Robb Elementary, in which 19 students and two faculty members were killed.
Two weeks prior to that, 10 people were killed by a racially motivated shooter at a supermarket in Buffalo, New York.
The 16-year-old's arrest is not the only potential mass shooting disrupted in the wake of the Uvalde shooting. Last weekend a fifth-grade student was arrested in Florida after threatening a mass shooting via a text message.
Police interviewed the boy and charged him with "making a written threat to conduct a mass shooting," according to the Lee County Sheriff's Office.
“This student’s behavior is sickening, especially after the recent tragedy in Uvalde, Texas,” Lee County Sheriff Carmine Marceno said in a statement following the arrest. “Right now is not the time to act like a little delinquent. It’s not funny. This child made a fake threat, and now he’s experiencing real consequences.”
Another 18-year-old was arrested in Florida over the weekend for allegedly threatening another mass shooting in Hillsborough County. The man in that case, Corey Anderson, posted a photo online of himself with what appeared to be a handgun, a rifle, and a tactical vest along with a caption that read "Hey Siri, directions to the nearest school."
Police later learned the guns were pellet guns.
“This man intentionally instilled fear into our community as a sick joke, but be warned, this is no laughing matter,” Hillsborough County Sheriff Chad Chronister said in a statement. “We will do everything within our power to apprehend, and pursue charges on those who make school-based threats. Protecting students is our greatest priority. We take school threats very seriously, if you see something suspicious, please contact us immediately.”
Mr Anderson was charged with a written or electronic threat to conduct a mass shooting or act of terrorism. If convicted he could face up to 15 years in prison.
Another man in Massachusetts, Justin Moreira, 29, was also arrested last weekend for allegedly making a school shooting threat over Facebook.
According to the Gun Violence Archive, the US has experienced 223 mass shootings so far this year. The archive defines a mass shooting as one in which at least four people are shot, excluding the shooter.