CDC security guards stopped White from driving into the campus on Friday before he parked near a pharmacy across the street and opened fire from a sidewalk. The bullets pierced “blast-resistant” windows across the campus, pinning employees down during the barrage. More than 500 shell casings were recovered, the GBI said.

Four CDC workers, who were not authorized to speak publicly, told CBS News under the condition of anonymity that they were "deeply disappointed and frustrated" by an apparent lack of leadership following Friday's shooting​.

Centers for Disease Control and Prevention employees in Atlanta on Monday recalled the harrowing moment a gunman fired nearly 200 shots at multiple office buildings last week, killing a responding police officer.