SOUTH PASADENA, Calif. — Two high school students suspected of plotting a school massacre in a Los Angeles suburb were arrested after investigators monitored their Internet activities and determined they presented a real threat, police said Tuesday.
The boys, ages 16 and 17, named three staffers they planned to kill and said they would target random students, police said.
‘‘They were making a huge, a huge plan of a school massacre,’’ South Pasadena Police Chief Arthur Miller said. ‘‘They just wanted to kill as many people as possible.’’
Miller said his officers saved lives by thwarting the attack in the quaint town of about 25,000 people known for its high-quality schools and community involvement in education.
School officials heard about the plot and notified police, who began watching the boys and monitoring their online activity. They had no weapons or date for a possible attack, but they were researching automatic weapons, handguns, knives and explosives, police said.
One boy allegedly said he had a relative with a gun that he might be able to get. Police contacted that relative, who said that the weapon was secured.
Miller said police realized how cold-hearted the plot was after interrogating the boys.
The two teenage boys were arrested on charges of making threats and conspiracy. They were being held at a juvenile facility.
Miller didn’t name the boys or provide information about the dynamic of their relationship.
Police expect to present their case to the district attorney later in the day.
The FBI joined the investigation to help search for evidence on the computers seized from the boys’ homes.
Police plan to have a larger presence on South Pasadena High School campus Thursday for the first day of school.