On Friday, police arrested a student who allegedly brought an AR-15 and ammunition to a Phoenix high school.
The student now faces “serious felony charges” for bringing the semi-automatic rifle, the same style of weapon behind the majority of the 21 deadliest mass shootings in the U.S. since 2006.
The incident happened at Bostrom High School, where the student was arrested in the main office around 1 p.m. on Friday, reports the Phoenix Police Department. The school went into lockdown as the arrested occurred. Authorities also uncovered additional ammunition in the student’s backpack and lunchbox, reports NBC News.