Students in Canton, Mass., are the latest to receive training that would give them a more proactive role in responding to a school shooter. Instead of hiding, they would barricade doors and learn counter techniques.
The program, called ALICE -- alert, lockdown, inform, counter, evacuate -- has been implemented in 300 schools since it was founded in the mid-2000s by former SWAT officer Greg Crane and his wife, a former school principal.
After the Columbine shooting in 1999, Crane said he realized the lockdown-only policies most schools have aren't enough to protect students if there is a shooter on the loose. By locking doors and hiding, students become easy targets, he said.