In order for a workplace investigation to be credible, investigators must deploy certain tactics to verify the accuracy of interview responses. In a previous post, Investigation Interview Questions to Determine Credibility, we reviewed the EEOC’s 5 factors to consider when determining statement credibility during investigation interviews. One of the toughest challenges to overcome during investigation interviews is the fact that witnesses may withhold or modify their responses to protect the subject- or the complainant and possibly even themselves. As investigators are often pressed for time when conducting internal investigations, they cannot afford to get hung up on determining who is correct in the “my story vs. their story” battle. We have compiled a list of simple tips and techniques investigators can use to determine investigation interview credibility.

Please note: It’s unlikely that the occurrence of a single deception indicator means that the interviewee is lying. Therefore, investigators should carefully observe for multiple deception indicators during interviews when determining statement credibility.

1. Consistent Statements

When asking questions related to the timeline of events involved in an incident, watch for inconsistencies or vague responses. This can be done by asking the interviewee to repeat or recall the order of events at different times throughout the investigation. Ask interviewees to go into greater detail about the incident-related events.  In the “Black Book of Lie Detection,” author Martin Soorjoo states that “when digging deeper, do so in an ‘interested’ manner rather than accusatory. Lying about detail requires a lot of thought and concentration.”

2. Body Language

Controlling physical actions is extremely difficult- hence the phrase “actions speak louder than words”. Pay attention to the physical tendencies displayed throughout the interview. Observe facial expressions and listen to the variations of pitch and tone in their voice. Body language that signifies lying varies across different cultures. Some of the common physical gestures exhibited by someone who is lying include: nail biting, touching their face- usually rubbing nose or covering mouth, avoiding eye contact, stroking the back of their neck, sweating, turning red in the face and fidgeting. In the “Black Book of Lie Detection,” author Martin Soorjoo states that “if an investigator believes the interviewee to be lying, don’t let on about it. Innocent people may become defensive if accused of lying and will demonstrate signs of stress through nonverbal and vocal cues- which can be mistaken as lying.”

3. Consider Your Own Bias

Investigators must remain neutral and refrain from making prior judgments in any investigation. Biases not only shape the attitude an investigator has towards the individual being interviewed, but can also influence the types of questions asked during investigation interviews. In the Business Management Daily article “Assessing Witness Credibility in Workplace Investigations,” they recommend bringing an additional investigator into the interview so that there’s an extra person to compare impressions and notes with. If personal bias is too difficult to overcome, consider asking an investigation manager to reassign the case to someone else to avoid sacrificing the accuracy of the investigation.

4. In the Eyes

Martin Soorjoo, author of the “Black Book of Lie Detection,” provides great insight into how an interviewee’s eyes can give them away. According to Soorjoo, an increased blink rate is often consistent with telling lies. Looking away and avoiding eye contact is tricky, as it may not always signal a lie is being told. When people lie, their pupils tend to dilate, which can be a useful indicator, as the body has no control over pupil dilation.

The free guide below includes an interesting “eye” test that can be used to decipher whether or not a lie is being told.

5. Incorporate Background Questions Into Interviews

At the beginning of an investigation interview, it’s beneficial to ask general background questions as a way to ease the interviewee into the environment. It’s likely that the person being interviewed will expect the questions to be based solely on the incident, therefore, background questions can be used to gauge the ‘normal’ responses and physical tendencies of the respondent. When investigators begin asking difficult, case-related questions it’ll be easier to accurately measure and monitor behavioral changes that indicate lying.

Investigators must be cautious during investigation interviews. People often mistake physical manifestations of stress as being indicators of lies being told. This sometimes happens to innocent people standing trial in a criminal case for a crime they didn’t commit. The irony is, the guilty defendant will have had plenty of time- sometimes years, to rehearse their lie. The innocent person will not have rehearsed because they are telling the truth and are scared because they have a lot to lose. Take this advice into consideration throughout ALL investigation interviews.

The interview element of a workplace investigation isn’t easy. Interviewing becomes increasingly difficult when there are conflicting responses from candidates you interview. Credibility can be sacrificed when there are too few or too many people interviewed. If the complainant and the subject are the only people to interview, it becomes one person’s word against the other. If there are a lot of witnesses, some may have conflicting stories due to bias. The EEOC recommends weighing the credibility of each person interviewed in order to find out what actually took place during the incident.

Factors to Consider:

The EEOC has put together a list of 5 factors to consider when trying to determine the credibility of statements and responses made during the interview process. However, it is also important to note that these are “things to consider” and not the “be all, end all” for determining credibility.

1. Inherent Plausibility:

Is the testimony believable on its face? Does it make sense? You want to watch for the presence and order of key facts presented by everyone interviewed. You may also want to consult any materials in the workplace that could back up the facts of the story- security videos, whereabouts of the employees in the workplace, timing of events, etc.

2. Demeanor:

Did the person seem to be telling the truth or lying? We have put together a helpful resource that you can download here called the “Black Book of Lie Detection”. Take a read through it to learn more about determining how to tell if someone is lying or not.

3. Motive to Falsify:

Did the person have a reason to lie? Does the person feel threatened for any reason? Once again, bias and opinion can sometimes get in the way of telling the truth. You need to consider any connections that people have to the incident or to the complainant and the subject. Could these connections cause them to lie because they know their friend will get hurt? Do they fear retaliation from others for being involved in the interview? Address these issues and enforce your zero-tolerance policy when it comes to retaliation in the workplace.

4. Corroboration:

Is there a witness (such as an eye-witnesses, people who saw the person soon after the alleged incidents, or people who discussed the incidents with him or her at around the time that they occurred) or physical evidence (such as written documentation) that validate the party’s testimony? The information gathered from these individuals needs to be weighed and considered for accuracy- if the witnesses have any bias towards either individual involved in the incident, chances are their story will reflect it. Watch for commonalities or discrepancies in witness stories and the claims made by the complainant and the subject in order to get a better picture of what took place during the incident.

5. Past Record:

Did the alleged harasser have a history of similar behavior in the past? Many times, past behaviour is predictive of future behaviour, but is not always the case. It is beneficial to be aware of repeat offenders in the workplace and what conclusions and actions were taken in their previous cases. Our internal investigation software solution, i-Sight, has the capabilities to let you know if the subject has committed other incidents in the workplace, maintains all case records and evidence in past cases and is readily available to you to consult should you need to.