The 14-year-old shooter who confessed to killing four people at Apalachee High School was allowed to leave his classroom with his belongings before returning with a rifle in his backback, the Georgia Bureau of Investigation said Thursday.

A 14-year-old boy used an AR-platform-style rifle in a high school near Atlanta, Georgia and killed two students and two teachers.

The state agency said Colt Gray took the weapon into the Barrow County school, which does not have metal detectors, on his own. “The assault-style rifle could not be broken down, but Gray hid it in his backpack,