Interviews and interrogations are the basic sources of information concerning issues such as crimes, where witnesses or suspects provide all evidence regarding what they know about the incident. Interviews tend to be friendly and conducted in a non-harsh environment, meaning that the interviewee is not locked up. They are commonly conducted with the witness. In contrast, an interrogation is conducted with the suspect, who may be in a specific room, such as a cell, and may not be carried out in a friendly manner. In our case, Sam might be the suspect.
Physiological methods and practices include techniques that involve body parts such as hands, eyes, head, posture, mouth, and lips, along with their physical responses during interviews. Psychological methods and practices involve thinking and the mind, for example, attitude and word composition.
During the interview or interrogation, the investigator should take note of any body changes. For example, 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 untrue. Forward movement of the head may also indicate that the subject is unwilling to provide information. Some suspects may experience stress during interrogation, causing their skin color to notably change, either to pale or white. This means that the subject is under tension, and the information given might not be correct; thus, the investigator must handle the stress first before obtaining information.
In psychological analysis, the thinking of the subject is examined in terms of how sentences are constructed, including the use of verbs, pronouns, and even nouns. For example, you can differentiate between people speaking the truth from those lying. “Ask a person to narrate what happened yesterday from morning to evening, then ask them to narrate what happened from evening to morning, and compare the two. If there is a contradiction, then there is deception.
When the subject is lying, it can be noted in their change in breathing patterns, increased heart rate, and emotional sweating on their hands, feet, and to a certain extent, the whole body. This can be analyzed using a polygraph, which measures changes in the body during stress or deception.
The use of the above physiological and psychological methods is important because they can provide information from a suspect more easily without causing harm, and the information collected is reliable since one can detect if the suspect is lying or not. 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 feelings and emotions, which should be analyzed during interviews and interrogations. Facial expressions can be micro or macro; micro is whereby facial expressions can be hidden for some time and revealed after 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 is pretending to be sad, hence he might be lying about the incident. Some people tend to shed crocodile tears, making them seem not guilty, and empathy can be extended to them, this should be noted by the investigator.
The 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 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 of obtaining 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 information, and thus, all of these must be employed effectively to obtain the intended information.