Suspicious 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.
Protecting Citizens' Privacy & Civil Liberties
The "If You See Something, Say Something™" campaign respects citizens' privacy, civil rights, and civil liberties by emphasizing behavior, rather than appearance, in identifying suspicious activity.
Factors such as race, ethnicity, and/or religious affiliation are not suspicious. The public should only report suspicious behavior and situations (e.g., an unattended backpack or package, or someone breaking into a restricted area). Only reports that document behavior that is reasonably indicative of criminal activity related to terrorism will be shared with federal partners.
How to Report Suspicious Activity
Public safety is everyone's responsibility. If you see suspicious activity, report it to local law enforcement or a person of authority.
Describe specifically what you observed, including:
Who or what you saw;
When you saw it;
Where it occurred; and
Why it's suspicious.
This information is adopted from DHS.gov