An active shooter training exercise was held Tuesday at LIU Post.

The drill brought together several Nassau County police with North Shore police departments, including from Brookville, Old Westbury, Muttontown and SUNY Old Westbury.

“Unlike a tactical team responding, it is going to be the patrol officers responding with the village set up here, we are going to be responding together,” says Old Westbury Police Chief Stuart Cameron.

The departments are learning how to respond properly together, even when members who respond come from different departments.

Cameron says the departments will get “great support” from the Nassau County Police Department since they are geographically isolated in the area. He says since active shooter attacks happen rapidly, they need to be prepared to respond together.

As part of the active shooter training, police are using real guns with paint marker bullets inside. They do not others, but they leave a mark, so they know if they got shot.

“The instructors are observing the whole scenario take place and they can go over with us after things we can do better, tactics we can do better,” says Brookville Police Department Corporal Thomas Gould.

The simulation is as realistic as it could be with police not knowing where or who is presenting a threat to the people in the building.

The training exercises are taking place through this week.