In forensic psychology, interviewing and interrogation are two of the most powerful tools used to uncover deception, collect evidence, and understand a suspect's behavior. Although these terms are often used interchangeably, they are very different psychological processes with their own goals, techniques, and effects on the suspect.

INTERVIEWING
An interview is described as a fact-finding dialogue, ideally non-leading, where the interviewer maintains neutrality and professionalism.

The Forensic Assessment Interview Technique (FAINT) is a scientific method used in this process. The interviewer creates a calm and controlled environment to notice signs of possible deception. Physical or emotional reactions—like sweating, bigger pupils, or changes in posture—are seen as fear of being caught, not always proof of guilt.

Good interviewers should:

  • Stay calm and avoid judgment.
  • Keep an open and honest body posture.
  • Avoid bias or asking leading questions.

In general, truthful people usually want to share information, while deceptive people often talk less or resist.


INTERROGATION
Interrogation is a structured method used by investigators when they reasonably believe that a suspect is guilty. It is designed to break down resistance and bring out a confession.  It is not a question-and-answer session; it's a persuasive process. The interrogator speaks 95% of the time, using repetition, emotional appeals, and leading questions. The goal is not just to collect facts but to push the suspect from denial to small admissions and finally to a full confession. In an interrogation, the interrogator controls the conversation.

There are 10 key aspects of interrogation:

  1. Start with a confident accusation.
  2. Block denials.
  3. Offer emotional justifications.
  4. Undermine resistance.
  5. Emphasize benefits of confession.
  6. Reduce fear of punishment.
  7. Compliment or humanize the suspect.
  8. Use persuasive/leading questions.
  9. Watch for signs of willingness.
  10. Move physically closer during key moments.


Verbal and Nonverbal Considerations: 
During interrogation, body language plays a big role. Certain nonverbal actions are seen as possible signs of deception, such as:

  1. covering the face or mouth,
  2. avoiding eye contact or keeping it unnaturally long
  3. fidgeting
  4. tapping feet
  5. sitting in a defensive posture
  6. A lowered head can suggest submission

On the other hand, gestures like unfolding arms or exposing the neck are considered signs that the suspect is becoming submissive and might soon confess.

In short, interrogation is not just about asking questions. It is a carefully structured psychological strategy where the interrogator uses both words and body language techniques to lead a suspect from denial toward confession.


Differentiate between interviewing and interrogation:

FEATURE INTERVIEW INTERROGATION
PURPOSE The purpose of an interview is to gather information. The purpose of an interrogation is to obtain a confession.
APPROACH An interview is non-accusatory and focuses on finding facts. An interrogation is accusatory and assumes guilt.
FLOW An interview is free-flowing and allows open conversation. An interrogation is highly structured and controlled.
SPEAKING RATIO Suspect talks about 95%, interviewer about 5%. Interrogator talks about 95%, suspect about 5%.
LOCATION Usually in a neutral setting. Occurs in the interrogator’s controlled environment.
MIRANDA WARNING Usually not required. Often required if custodial and accusatory.
BODY ZONES Personal-social distance is maintained (about four feet). Interrogator may enter the intimate zone (within 18 inches).
NOTE-TAKING Allowed as long as it is consistent. Discouraged to avoid showing uncertainty.

References:

  1. Bandura, A. (1977). Social learning theory. Prentice-Hall.
  2. Inbau, F. E., Reid, J. E., Buckley, J. P., & Jayne, B. C. (2013). Criminal interrogation and confessions (5th ed.). Jones & Bartlett Learning.
  3. Miller, N. E., & Dollard, J. (1941). Social learning and imitation. Yale University Press.
  4. Nathan, D. L., & Fleisher, W. L. (2004). Forensic interrogation: The art and science of interviewing and interrogating. Lawyers & Judges Publishing.
  5. Vrij, A. (2008). Detecting lies and deceit: Pitfalls and opportunities (2nd ed.). Wiley.