donotSuspicious activity is any observed behavior that could indicate terrorism or terrorism-related crime. This includes, but is not limited to:

  • Unusual items or situations: A vehicle is parked in an odd location, a package/luggage is unattended, a window/door is open that is usually closed, or other out-of-the-ordinary situations occur.
  • Eliciting information: A person questions individuals at a level beyond curiosity about a building’s purpose, operations, security procedures and/or personnel, shift changes, etc.
  • Observation/surveillance: Someone pays unusual attention to facilities or buildings beyond a casual or professional interest. This includes extended loitering without explanation (particularly in concealed locations); unusual, repeated, and/or prolonged observation of a building (e.g., with binoculars or video camera); taking notes or measurements; counting paces; sketching floor plans, etc.

Some of these activities could be innocent—it’s up to law enforcement to determine whether the behavior warrants investigation. The activities above are not all-inclusive, but have been compiled based on studies of pre-operational aspects of both successful and thwarted terrorist events over several years.