CHICAGO (CBS) — There have been 23 school shootings in the United States so far this year. The most recent school shooting happened in Noblesville, Indiana last Friday.

As a result, more schools are requiring teachers to get special training to protect their students.

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CBS 2’s Jeremy Ross says the training can be shockingly realistic.

Police officials say the active shooter drills are becoming more serious as gun violence in schools continues to become more common place.

Sargent Kyle Brown of the Lake County Sheriff’s Office says it is the fifth year they’ve reached out to schools like Ingleside’s Big Hollow Middle School to instruct educators how to curtail casualties in active shooter simulations.

“I don’t like that I have to teach this. I teach this because it’s a necessary thing to teach,” explains Sgt. Brown.

For Safety reasons educators wear protective goggles and masks and use plastic pellets to simulate ammunition. While it’s just a drill, the stress is real.

“It’s pretty scary to think about what I’d have to do,” said Meredith Perry, a teacher at the school.

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Perry is one of many teachers learning that it takes, on average, about five to six minutes for police to get to mass shootings, which they describe as an eternity when lives are at stake and adrenaline is high.

Teachers practiced barricading their classrooms and learning when to evacuate, rushing to nearby emergency exits while trying to keep calm.

“At that point, you can evaluate or you can swarm the bad guy,” explained Sgt. Brown.

Another option, police say, is to overpower the man with the firepower.

Teachers say the tools they are learning are necessary, but they hope to never have to use them in the classroom.

“We don’t want to lose our sense of outrage that we even have to do this,” stated Perry. “But we still do it professionally.”

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Funding for the training comes from the Sheriff’s Office, which trains schools, houses of worship, and businesses.