Deception usually occurs in speech patterns such as speeding up or slowing down, talking louder, talking softer, coughing or clearing the throat. Other non-verbal clues can include closing the mouth tightly, pursing lips, covering the mouth with a hand, biting the lips, excessive blinking of the eyes, and chewing objects.
During the initial part of the interview, interviewers should ask open and general questions that create friendly environment in order to assess a baseline of behaviour. During this process, interviewers should not stare at the person being interviewed or call attention to a person’s behaviour. Interviewers should be observing the timing and consistency of behaviour and should note clusters of behaviour.
You must exercise strong caution such that there will be no misinterpretations of behaviour due tonnervousness or stress. Witnesses may also provide false oaths of honesty. Examples would be “I swear to God.” Or, they may offer character testimony such as “You can check with my brother or the pastor.” A person engaged in deception may answer a question with another question or may be overly respectful toward the interviewers.
If the interviewers come to believe that the interviewee is engaged in deception, efforts should be made to discover the reason for such deception. More experienced criminals may not exhibit some of the deceptive verbal or nonverbal behaviours mentioned previously.These days, information can be found on numerous websites by searching terms relating to deception/ interviews. These websites describe and discuss these same physical, verbal and non-verbal signs of deception with this knowledge, it is entirely possible that experienced criminals can further disguise their activity or even manipulate the interview process.