Lockdown Procedure (Definition)

For some emergencies evacuation isn't a good option. When armed intruders are near or in a building, an lockdown procedure may be a suitable response. Doors and windows are locked to restrict an intruder's mobility.

Lockdown procedures are often adopted and practiced by schools as one of the few countermeasures possible for the risk of school shootings.

When the threat does not involve armed intruders, a shelter-in-place procedure may be more appropriate.