This is how law enforcement is trained to react to active shooters

ALEXANDRIA, Va. (ABC7) — Twelve people were killed during Friday’s shooting rampage at the Virginia Beach Municipal Center.

More people could have died if law enforcement officers had not stormed the building just two minutes after the 911 call was made.

The shooter was a public works employee who knew the building and was armed with two handguns, extended magazines, and a noise suppressor.

MORE: Did gunman's 'silencer' make a difference in the carnage?

“With a suppressor, you might not hear the gunshots, and you might not be able to identify the area the gunshots are coming from,” said Bill Gleason of the Law Enforcement Legal Defense Fund.

The Law Enforcement Legal Defense runs a “shoot or don’t shoot” simulator in Alexandria, which showed us how law enforcement officers respond to active shooters. Friday’s gun battle lasted 36 minutes.

“It’s amazing it lasted that long and that suppresser obviously contributed to that,” Gleason said.

One officer was shot but saved by his bulletproof vest.

The police eventually shot and killed the gunman before he could kill any more people.

“We have to be aggressive, put ourselves in harm’s way. We have got to go in and stop the killing,” Gleason said.

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