Hall County Sheriff’s Deputy Glenn Watson and his partner trained their air pistols on Cpl. Chris Farmer and blasted him with a barrage of tiny, round, green rubber pellets in Pam Moore’s biology classroom Wednesday at East Hall High School.

With school out for the day and students and faculty gone, nearly 30 deputies lined up for their turns in an "active shooter" training exercise, with the face mask-wearing Farmer playing the role of a rampaging school shooter roaming from room to room.

Afterward, Watson, who got pelted once in the arm with a pellet fired from Farmer’s gun, critiqued his turn at the 60-second drill.

"I wish I hadn’t gotten hit, and I wish I had hit him more," Watson said.

With Virginia Tech, Columbine and other mass shootings making such law enforcement training commonplace, sheriff’s officials have taken to conducting the drills inside schools and other public buildings. This year is the first time air pistols modeled closely after the agency’s standard issue Glock .40-caliber handguns were used in the drills, lending more realism to the simulation, Lt. Michael Myers said.

The active shooter drill is conducted with every officer, not just SWAT members. That’s because if a gunman is on the loose, law enforcement doesn’t have time to wait for SWAT to mobilize. Whoever shows up first, from school resource officers to road deputies to supervisors, must go in.

"What we’ve learned from these tragedies is that the worst thing we can do is stand outside the school and do nothing while children are shot," Myers said. "Law enforcement is most effective in this situation when it presses the fight toward the aggressor."

Pressing the fight would typically begin as soon as two deputies are on the scene. The approach is the opposite of "containment" tactics used when there is an armed person who may be threatening but has not fired a shot.

Once the shooting starts, deputies are taught, immediate action is necessary and adrenaline takes over for deliberation.

Myers said the little green pellets are great "self-correcting" tools for trainees.

"Once they get hit two or three times and it stings real bad, they realize they’ve got to press forward — they can’t just stand around," he said.

Training officer Sgt. Bonner Burton watches each two-deputy team, ordering them to "press the fight" and keep moving. Afterward he breaks down their performances in succinct critiques.

Wednesday’s group of trainees spent four hours at the school going over tactical movements, using cover, clearing rooms and working as teams.

"There’s always things you can build upon to improve," Sgt. Mark Blihovde said. "That’s why we’re doing this training.

"Hopefully it will never happen in Hall County, but we’ve got to be prepared for the worst if it happens."