Two 15-year-old girls arrested over chilling plot to carry out California high school massacre

Published: 06:21 BST, 22 October 2026 | Updated: 06:30 BST, 22 October 2026

Two 15-year-old girls have been arrested over an alleged plot to unleash a school shooting at a California high school after investigators uncovered months of disturbing online discussions.

The teenagers, both from Riverside County, are accused of spending several months researching previous school shootings and conspiring to carry out a horrific massacre at Corona High School, according to police.

The investigation began on October 6, when the FBI alerted the Corona Police Department and Riverside County Sheriff’s Office to threatening social media communications targeting the school.

Investigators moved swiftly, arresting the first girl, a 15-year-old student at Corona High School.

But the investigation did not end there. Detectives launched an extensive search for evidence, executing numerous search warrants, examining electronic devices and communications, and searching several homes across Riverside County.

Their inquiries led them to a second 15-year-old suspect, attending nearby Norco High School who was subsequently arrested.

Both teenagers remain in custody on suspicion of conspiracy to commit murder, police said.

Investigators said the girls had spent several months researching school shootings and discussing how they might carry out an attack at Corona High School on an unspecified future date.

Two unidentified teenage girls have been arrested on suspicion of conspiring to carry out a school shooting at Corona High School, according to police

The investigation began on October 6, when the FBI alerted the Corona Police Department and Riverside County Sheriff’s Office to threatening social media communications targeting the school

Authorities also uncovered conversations about obtaining weapons, raising further concerns about how far their suspected plans had progressed, although detectives said the pair had thankfully not managed to acquire any.

Searches of multiple homes across Riverside County, along with examinations of electronic devices and messages, formed part of the investigation.

No firearms were recovered during the searches, according to police.

The alleged plan has raised fresh concerns about the role online communications can play in identifying potential threats before violence occurs.

However, authorities have not disclosed what motivated the alleged plot, whether the teenagers had identified particular victims or how advanced their preparations may have been.

It also remains unclear when the alleged attack was intended to take place.

The investigation is continuing, with the FBI, Riverside County Sheriff’s Office and Corona-Norco Unified School District working alongside Corona police.

The case is all the more striking because both suspects are girls, an unusual profile in investigations involving planned school shootings.

Detectives arrested a 15-year-old female student who attends Corona High School. After searching several homes in Riverside County, California, going through electronic devices and messages, detectives identified and arrested another 15-year-old girl who attends Norco High School

Research cited by NPR has highlighted the rarity of female perpetrators. FBI data covering active-shooter incidents between 2000 and 2019 identified 13 female perpetrators among 345 attackers.

Corona High School serves students in grades nine through 12 and is part of the Corona-Norco Unified School District.

The arrests come amid persistent fears over school violence in the United States, where investigators increasingly face the challenge of identifying threats before they turn into real-world attacks.