Police say a high school student from Montgomery County, Maryland who brought a gun to his school last week was also in possession of a large weapons cache at his house that included grenades, an AR-15-style rifle, and a detonator for C4 landmines.
As reported by ABC News 7's Kevin Lewis, police also say the student had produced a list of grievances that he felt toward both his school and his classmates.
Fox 5 DC reports that the student, an 18-year-old Clarksburg, Maryland resident named Alwin Chen, was arrested last week after police pulled him out of class and found that he was in possession of both a gun and a knife.
Police had been asked to come to the school after its administration received a tip about a student who allegedly brought weapons with him into the building.
Chen is currently being held in custody without bond.
Watch Fox 5 DC's video on Chen's arrest below.