Assessing credibility

Image courtesy of Stuart Miles and

You’ve completed your workplace investigation. Now it’s time to draw your conclusions. How do you decide who is telling the truth, and who is lying?

Assessing credibility is the most difficult task you’ll face in a workplace investigation. But guidelines exist. The Equal Employment Opportunity Commission offers five fundamentals for determining who’s telling the truth:

  1. Inherent plausibility: Is the testimony believable on its face? Does it make sense?
  2. Demeanor: Did the person seem to be telling the truth or lying?
  3. Motive to falsify: Did the person have a reason to lie?
  4. Corroboration: Is there witness testimony or physical evidence (such as written documentation) that corroborates the party’s testimony?
  5. Past record: Did the alleged harasser have a history of similar behavior in the past?

Of course, there are other factors to consider, as well.

Is the witness you’re interviewing a friend of the accused or friend of the complainant – or, in contrast, has that individual been in conflict with either of them? Ideally, as an investigator, you want potential witnesses without personal ties to either party, and no vested interest in the outcome.

What about your biases? As an investigator, you have to set your own biases aside. You can’t be influenced by the circumstances surrounding the allegations you’re investigating. For example, statistical evidence shows that police are more likely to stop black motorists for minor traffic offenses because officers assume they are more likely to engage in criminal activity. What preconceptions do you harbor? What biases might you have toward someone accused of a workplace violation?

Establish rapport
Don’t go on the attack from the outset. You will be more effective if the suspect believes you are open-minded. Try to establish rapport, so the witness will relax and trust you. Be aware, too, that some apparently deceptive behaviors could be an innocent person’s response to the stress of being interviewed.

If you do detect a deceptive behavior, try not to let the person know you suspect him of lying. That might make an innocent person defensive and prone to exhibit signs of stress, which could then be interpreted as cues that he is lying. If you suspect a lie, probe deeper, but act interested rather than accusatory.

Deceptive behaviors
What kinds of deceptive behaviors should you look for when interviewing witnesses? And what kind of behaviors should be discounted?

We’ve all heard that a person with a closed posture, such as crossed arms, is on the defensive. In reality, that person might merely be comfortable in that position, or perhaps he or she is cold. Similarly, we’ve been told that failure to initiate eye contact indicates deceptiveness. That isn’t necessarily the case. There could be more than one reason someone isn’t looking at you, ranging from simple discomfort to lack of self-confidence.

Be cognizant of cultural differences, as well. Some behaviors are universal across culture, ethnicity and nationality, but others have a positive meaning in one culture and a negative meaning in another.

A single deceptive behavior isn’t telling. As an investigator, you need to look for clusters or groupings of deceptive behaviors.

Examples of deceptive behaviors:

  1. A verbal or nonverbal disconnect: The subject responds to your question by saying “no,” but shakes his head up and down in an affirmative manner.
  2. The subject hides her mouth or her eyes.
  3. The subject fidgets or rearranges his position in response to your question.
  4. The subject sidesteps the question, answers your question with a question that doesn’t correspond to what you asked or goes on the attack.
  5. The subject fails to deny committing an act of wrongdoing, hedges her denial, or hides the denial inside a long-winded answer.
  6. The subject goes on the attack.
  7. The subject invokes religion.
  8. The subject tries to demonstrate what an upright, outstanding person he is.
  9. The subject makes inconsistent or contradictory statements, or his or her chronology of events differs from that of other witnesses.

Assessing credibility isn’t easy. But employing the guidelines mentioned above can help you make decisions about credibility with confidence.

For more information on assessing credibility, we recommend the book Spy the Lie by Philip Houston, Michale Floyd and Susan Carnicero.

Next: Reporting factual findings to the employer.

Previous articles in this series:

Workplace Investigations, Part I: The Basics

Yes, You Need a Workplace Investigation

How to Conduct a Neutral Investigation

If you have questions or concerns about workplace investigations, contact Johnson Employment Law for guidance, 949-238-8044.