Police are greeting students on the first day of classes in the Los Angeles suburb where two teens allegedly plotted a high school massacre.
Officers were in force Thursday at South Pasadena High School as students began the school year without two peers.
The 16- and 17-year-old boys have denied charges they threatened another student.
Police say they could face other charges related to an alleged plot to target three high school staffers and kill as many students as possible.
The boys were arrested after police monitored their online activity and determined they presented a serious threat.
The boys didn't have a specific attack date or weapons, but police say they were researching how to arm themselves.
The father of one accused boy says his son meant no harm.