Next we will look at each layer of security and the types of security questions that should be considered for each area. The provided questions apply principles of Crime Prevention Through Environmental Design (CPTED) and focus on issues pertinent to potential mass casualty incidents.

CPTED is based on the idea that a physical environment can positively influence human behavior through:

• Natural surveillance: Ability to see what is occurring in a particular setting;
• Natural access control: Ability to restrict who enters or exits an environment; and
• Territorial maintenance: Ability to demonstrate ownership of and respect for property.

Checklists for each area assessment are provided at the end of this section.