BRATTLEBORO -- More than 40 law enforcement officers from Vermont and New Hampshire took part in a training at Brattleboro Union High School Friday to go over the best practices in case there is an active shooter in a public building.

Officers from Brattleboro, Wilmington, Hinsdale, N.H., as well from the Vermont State Police and Windham County Sheriff's Department attended a one-hour seminar and then trained in the halls of the high school.

The training was organized by the Brattleboro Police Department. Brattleboro Capt. Michael Fitzgerald said the training was called to make sure anyone who might show up to an active incident is up to date on the accepted procedures.

"If we ever have to respond to something like this it is going to be chaotic and every incident is going to be a little bit different," Fitzgerald said. "As much as we can get to know each other, and all understand the best practices, it will make it better for everyone."

The training was led by Vermont State Police Sgt. Steve Otis, a member of the VSP Tactical Support Unit. Otis talked for about an hour in the high school auditorium before the police officers went out into the hallway to train.

Otis said the mass shooting at Columbine High School, when two gunmen killed 13 people and injured 24, changed the way officers respond to an event. Prior to Columbine, he said, officers were trained to secure the perimeter and wait for support. Following that event officers are now trained to enter a building with an active shooter as soon as possible.

Otis listed the mass shootings that occurred in the United States since Columbine on April 20, 1999. He talked about the shooting at the Trolley Square Mall in Utah that left five dead; the mass killing at Virginia Tech where 32 people died; Fort Hood, Texas, when 13 people were killed on a military base; the mass murder in an Aurora, Colo., movie theater that left 12 dead; the shootings in Tucson, Ariz., where six people died; and finally, Newtown, Conn., where a gunman killed 20 children and six adults at Sandy Hook Elementary School.

Each incident was different, Otis said, with different motives and strategies, and he said it was important for the officers to be prepared but also to be flexible and open to an ever changing situation.

"Have a plan," he said. "It is always better to do something than do nothing."

According to Otis about 75 percent of the law enforcement officers in Vermont have attended the training, which is based on procedures developed by the National Tactical Officers Association.

"Vermont is a small state and any time there will be a lot of officers from different agencies," Otis said. "It is important that everyone is on the same page."

Fitzgerald said the training Friday was just one in an ongoing effort to prepare for an incident.

Next month local agencies and town departments will hold another exercise at the high school to go over procedures.

"There is a lot of coordination that goes on when something like this happens," he said. "The event might only last 10 minutes but how it affects people's lives is indefinite."

Howard Weiss-Tisman can be reached at hwtisman@reformer.com; or 802-254-2311, ext. 279. You can follow Howard on Twitter @HowardReformer.