CUPERTINO, Calif. -- Authorities were trying to determine why a college student described as "choir boy" from a good home was allegedly scheming an elaborate mass killing with an arsenal of bombs and weapons.
Police on Tuesday evacuated more than 10,000 students and 1,000 staff members at De Anza College after learning of the possible "Columbine-style" attack.
Al DeGuzman, 19, faces more than 50 felony counts, authorities said. The school was to reopen Wednesday.
Police said they found 30 pipe bombs, 20 Molotov cocktails and several weapons and ammunition stashed in his bedroom at the San Jose home where he lived with his parents.
"This was an elaborate plan for a mass murder," said San Jose Deputy Police Chief Mike Miceli. "He had a game plan and was very intent on doing what he was going to do."
Police have not determined a motive, but said they believe DeGuzman had planned to blow up the Cupertino college on Tuesday. The school, 45 miles south of San Francisco, has about 26,000 students.
Police arrested DeGuzman late Monday after a photo lab clerk at a San Jose drug store tipped them to suspicious pictures of a man posing with what appeared to be an arsenal of explosives.
When DeGuzman arrived at the drug store to pick up his prints, the clerk stalled him by asking for identification until police could arrest him, Miceli said.
Inside DeGuzman's room, police said they found a diagram of the campus and other notes indicating he intended to begin planting bombs Tuesday morning and launch his attack during the lunch hour in the school's main cafeteria.
Nothing suspicious turned up during a daylong search of the 65 buildings on campus.
Police said they also found an audiocassette recording in which DeGuzman sympathized with two gunmen who killed 13 people and themselves at Colorado's Columbine High School in April 1999.
Police said the recording also included apologies to his parents, friends and the media.
"The tape recording was just bone chilling," Miceli said.
Neighbors described DeGuzman as an unassuming kid from a good home, saying they thought he would grow up to be an engineer.
"He's a choir boy, like a straight-up school boy," said Bobby Playa, 18, who attends the high school where DeGuzman was editor of an award-winning yearbook.
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