Interviews and interrogations forms the basic sources of information concerning an issue such as a crime, where by the witness or the suspects gives all evidences with regard to what they know about the incident. Interviews tends to be friendly and not in a harsh environment; meaning that the interviewee is not locked up and is commonly done with the witness, whereas interrogation is done to the suspect who may be in a specific room such as a cell and may not be in a friendly way. In our case, Sam might be a suspect.
Physiological methods and practices include techniques that involve the body parts such as hands, eyes, head, posture and even mouth and lips and their physical response during the interview. Psychological methods and practices include thinking and it involves mind for example attitude, and word composition.
During the interview or interrogation, the investigator should keep note of any body changes such as movement of the hand to other body parts like eyes may imply that the subject does not want to look at the interviewer/interrogator and any information given may be regarded as not true. Movement of the head forward may also mean that the subject is not willing in giving information. Some suspects may be under stress when being interrogated such that their skin color changes notably either to pale or white, this means that the subject is under tense and the information given might not be correct, thus the investigator must handle the stress first before getting information.
Under psychological, thinking of the subject is analyzed as to how the sentences are constructed, use of verbs, pronouns and even nouns. For example, you can differentiate between people speaking the truth from those lying. Tell a person to narrate what he does or happened yesterday from morning to evening, tell him to narrate what he does or happened from evening to morning and compare the two. If there is contradiction then then there is deception.
When the subject is lying, it can be noted in their change in breathing patterns, rate of the heartbeat increases, some sweat emotionally on their hands, feet, and to a certain extent of the whole body. This can be analyzed using polygraph which measures the changes of the body when in stress of deception.
The use of the above Physiological and psychological methods are important because they can provide the information from a suspect more easily without causing harm and the information collected is reliable since one can be able to detect if the suspect is lying or not lying. Also, since the information gathered is primary i.e. from the suspect directly then the information can be relied upon.
Communication is the way a person conveys the message to another person through the use of words, gestures and even facial expression. Facial expression is the silent way of revealing the feelings and emotions which should be analyzed during the interviews and interrogations. Facial expressions can be micro or macro; micro is where by facial expressions can be hidden for some time and revealed in a while usually in a very short period whereas macro can be revealed for a long period. Facial expressions such as a moment of sadness followed by a bit of laughter may imply that the subject may be pretending to be sad hence he might be lying on the incident. Some people tend to shed crocodile tears such that they can be seen as not guilt, and empathy can be extended to them, this should be noted by the investigator.
Use of words such as pronouns like “we” in the conversation may mean that the subject was not alone. Omissions of words such as “then”, “later”, “after” may imply that the subject is trying to overlooking other things during the period of investigation hence the subject needs to be investigated further and may be interrogated.
The rationale of using these tools is that one can witness the reactions of the suspect towards questions asked and it will be easy to judge whether the suspect is telling the truth or lying. The evidence collected by these tools is easy to work with and the judgment that one can make may not be biased since the investigator has a chance to witness the evidence revealed by the suspect/witness during interview and interrogation.
Physiological and psychological methods and practices form the basis in getting information from the suspect/witness during interviews and interrogations; they are silent ways of gathering information. Verbal and non-verbal communication tools are unique ways to reveal the information and thus, all these must be employed effectively in order to get intended information.