The suspect had entered the facility to report to work as usual, before opening fire on victims inside and outside of the facility. The Harford County sheriff stated that calls of "shots fired" came from the Rite Aid distribution center at approximately 9:06 am. EDT. Deputies responded at 9:09 am. Officers reportedly never discharged their weapons while responding to the scene. Agents from the Baltimore offices of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and the FBI responded to the scene.