Arcadia, Monrovia, and Duarte schools all forced to lock down this week due to phoned in threats of a gunman on 4 separate campuses. On Thursday, September 12, the caller contacted Arcadia Police Department, reporting "he was at Arcadia High School and that he was going to start shooting students with an assault rifle." A second call was received during the police search of the campus that told officers to back off or they would be shot. No suspects of weapons were found.

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