By Anna Meiler

BOSTON (CBS) – At a moment’s notice, Massachusetts State Police have to be ready to respond to anything. That includes running towards an active shooter.

“It’s not a perception, it’s a reality that these types of incidents are happening more often and unfortunately we’re seeing larger and larger victim counts which is awful,” said Trooper Sean Barry, a trainer for the Special Tactical Operations Team, which responds to the most dangerous situations across the state.

“The STOP Team has grown over the years, we have a very high call volume in addition to training,” Barry said.

WBZ got an exclusive, behind the scenes look at how the STOP Team is training State Police recruits to respond to an active shooter. Training that is more critical now than ever before.

State Police STOP Team trains for active shooter (WBZ-TV)

“The three largest active shooter events have happened in the last five years,” Barry said. “Today we’re actually bringing them out into an environment that they could potentially respond to, a large building unfortunately we’ve seen it a lot in schools and hospitals and workplaces.”

The recruits navigate through stairwells and rooms and use Simunition pistols similar to the weapon they’ll use in the field.

“It’s very realistic,” Barry said. “Heart rates are up, they’re breathing hard, they’re breathing fast.”

“We don’t want the first time of them seeing a situation like this as being an actual active shooter event. We want to imprint them with the best training and tactics possible.”

Whether it’s a plastic pellet or a real bullet, the recruits are taught to push forward after they’re hit.

“We want them to fight through it, deal with the threat, end the threat and then be able to treat themselves,” Barry said.

State Police STOP Team trains for active shooter (WBZ-TV)

With each tragic event, police tweak their training methods and security measures. After the mass shooting in Las Vegas, the STOP Team began looking at entertainment venues in Massachusetts very differently.

“We’ve looked at the situation extensively, we’re already talking with our partners at large venues so that if an incident like Las Vegas happens we already know what everybody’s roles and responsibilities are,” Barry said.

The STOP Team knows the question is not if, but when they will have to respond to a critical situation. And when that time comes they’ll be ready to save lives.

“We’re always trying to increase our response and better ourselves so we’re at the cutting edge,” Barry said.

Anna Meiler