Dartmouth High School teachers and staff put their emergency response skills to the test at a March 29 active shooter drill.

The drill involved the use of the A.L.I.C.E. protocols, a set of tiered responses to emergency situations the district uses in all of its schools. It stands for Alert, Lockdown, Inform, Counter and Evacuate, and empowers teachers and students to adapt emergency decision-making based on a particular situation.

In one classroom, English teacher Will Higgins showed others a door he barricaded using a bike rack hook, a two-by-four, and a carabiner. It prevented two administrators and a police officer from entering the room.

Social studies teacher Jamie O’Neil's Barracuda Intruder Defense System also prevented entry into her classroom. Her dad found the device after seeing it on television.

English teacher John Cronin raised the question of why run if doors can be secured.

“There is no sense of staying if someone is on another floor," said special education teacher Brian Crowley.

Teachers also practiced decision-making skills. The school is equipped with a communications system that can be used to track a threat and communicate the threat's location.

During the drill, Principal Ross Thibault could be heard telling teachers where the “shooter” was, giving some teachers the chance to safely evacuate.

O’Neil said she feels more confident after having practiced the procedures.

“I actually have been involved with trying to get A.L.I.C.E. in the school for many years on the safety committee and I am thrilled that it’s finally came to fruition,’’ O’Neil said. “I look forward to training the kids.”

Dartmouth police officer Craig Pimental fired blank rounds in different areas of the building so teachers could hear what a gunshot sounds like during an optional part of the exercise.

After the session ended, Pimental said teachers had done a great job, and stressed the importance of individual decision making in choosing to run, hide, or fight in an emergency.

Teachers and staff came up with ways to improve the procedures, like solving issues they found with stairwell names and shortcomings in the communications system.

Superintendent Bonny Gifford said the drills were already planned for the spring, but in the wake of the Parkland, Florida school shooting, definitive dates were set.

Officials will be discussing introducing the training to the middle school and elementary administration, and age-appropriate training for younger students.