What type of behavior might an "informed observer" be trained to look for?

An "informed observer" is trained to identify unusual or suspicious behavior that deviates from the norm. This focus is crucial in security contexts, particularly in environments like airports or transportation hubs where threats can emerge unpredictably. By being vigilant and attentive to behaviors that stand out, an informed observer can potentially identify individuals who may pose a risk, allowing for timely intervention.

Unusual behavior can include actions such as someone lingering in an area without a clear purpose, avoiding eye contact, or showing signs of anxiety when questioned. Recognizing these nuances is part of the informed observer's skill set, enabling them to contribute effectively to overall security efforts. Such training emphasizes the importance of awareness and critical observation to prevent potential security incidents before they escalate.

The other options, while relevant to social norms and operational practices, do not focus on the specific skills that an informed observer needs to develop to maintain safety and security.