ALTURAS, Calif. -

A student from Modoc High School who police said may have been planning a mass shooting was in court Tuesday afternoon.

The investigation began on Sunday, Dec. 16 when Modoc County law enforcement said a "violent incident" occurred at a residence.

This incident culminated in the detainment of a juvenile student where he was taken by the county Behavioral Health services for a mental evaluation. After the evaluation, the student was sent to a mental health facility outside of Modoc County for treatment.

An investigation was launched after reports surfaced that the student was planning a "mass casualty shooting" at an unknown location in Modoc County for Friday, Dec. 21.

Law enforcement learned on Dec. 19 that the intended targets of the shooting were specific individuals at Modoc High School as well as family members.

Officials also learned that  the student made comments related to the shooting in Newtown, Conn.

A day after the initial incident at the residence, a search warrant was served at the student's home. On Dec. 18, a second search warrant was served at Modoc High School in an attempt to obtain more evidence. During the search on Dec. 18, three computers were seized for examination.

On Friday, the student was released from the mental health facility and immediately turned over to police custody. His arraignment was Tuesday afternoon. The unidentified student is facing two counts of assault with a deadly weapon and charges of making criminal threats.

Meanwhile, the FBI is still investigating the student's computers. Police have been present at all three schools in the Modoc Joint Unified School District since classes resumed Monday.