DENISON, Texas (KXII) -- The halls are quiet and calm at B. McDaniel Intermediate School in Denison, but in an instant, it could change.
An active shooter is on the loose. But this is just a drill.
"Loud noises people screaming other officers giving orders a lot of moving parts its really great training to go through it on a live base," says Denison Police Officer Jae Ricketts.
Local law enforcement agencies received free active shooter training from a nationally recognized and federally funded group called ALERRT.
"This training here puts everyone on the same page, same sheet of music, so that when you go in here we all understand the tactics and principals you're trying to accomplish," says ALERRT instructor Douglas Herrington.
ALERRT instructors say these officers will not only focus on the active shooter, but address the medical needs for the victims.
"Once we end the threat, that's when the real work begins," says Herrington. "Now we gotta start saving all these victims in here."
"To throw in the medical mix and the arterial breathing and the EMT side of it is one cool for us but also difficult for us to grab on a quick basis," says Ricketts.
Columbine, Sandy Hook, San Bernardino and Dallas Police. Situations these officers are training for but hope they will never experience in their hometown.
"It's all about training for the worst," says Ricketts. "If something does happen like this we are prepared."