Observation of non-verbal responses should begin at the start of the interview and continue throughout. Non-verbal cues, such as posture, facial expressions, and gestures, can provide critical insights into the interviewee's emotions, truthfulness, or reactions to specific questions. These cues are essential in identifying discrepancies or behaviors indicative of deception.

ASIS Certified Protection Professional (CPP®) References:

Interview and Interrogation Techniques: CPP materials highlight the importance of observing both verbal and non-verbal behaviors throughout the entire interview process.

Behavioral Analysis in Investigations: Non-verbal cues are emphasized as vital for understanding interviewee responses and detecting potential dishonesty.