Nearly four months after a gunman entered Ronald E. McNair Discovery Learning Academy, DeKalb County police, the FBI and other local, state and federal agencies will team up at 11:30 a.m. Tuesday for an "active shooter" training exercise.

“The recent McNair incident emphasized inter-agency communication and cooperation as being critical components for the successful response to a school-related active shooter incident,” DeKalb police spokeswoman Mekka Parish said. “A primary goal of the exercise is to improve each organization’s level of awareness and preparation in the event another incident of this nature occurs in DeKalb County.”

The alleged gunman in the August 20 incident at McNair, 20-year-old Michael Brandon Hill, was taken into custody after entering the school with an AK-47, barricading himself in the front office and firing shots at police as officers arrived at the school near Decatur. No one was injured.

Participants in Tuesday’s exercise at the Emory Conference Center on Clifton Road will also include Atlanta police, Emory University, DeKalb sheriff’s deputies, the Georgia State Patrol, the Georgia Emergency Management Agency, the GBI and agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.