“Liar, liar, pants on fire!” If ONLY it were that easy to detect falsehoods. I mean seriously—there is no way even a rookie detective is going to miss flaming pants. Unfortunately, interviewing witnesses and gauging veracity is a more nuanced and trickier business. One I took a close look at when writing And By Fire.
People know when they are lying. They know when they are withholding information. But how do trained interviewers—police detectives like my DIs Parker and O’Leary for example—figure that out?
It certainly isn’t easy. But physiological stress can cause a witness to react in ways that are telling. So, when DIs Parker and O’Leary interview a bystander or a possible killer—just like their real life counterparts—they pay attention to 1) body language /physical reactions; 2) the tone and type of their interviewee’s verbal responses.
Let’s start with the non-verbal tells. None of these examples are “gotchas” by themselves, but any or all of them can indicate lying, and they are certainly things a trained professional will be watching for.
👓 Is a witness being evasive in terms of eye-contact, body posture or both?
👓 Are they acting bored—slouching and yawning is not how most of us would react to being interviewed by the cops right?
👓 Is the witness fidgeting—for example doing a lot of shifting around in her chair as if she can’t sit still, touching her hair?
👓 Is the witness’s physiology betraying him? There are a lot of things about our bodies we just can’t control—including some physical reactions triggered by being nervous or stressed. For example . . .
Maybe the witness is licking his lips or clearing his throat—either of which may indicate his mouth is dry because he is nervous.
Has he asked to use the bathroom so many times that even a couple of pints with lunch won’t explain it?
Other “tells” that might indicate stress or lying can include: repeatedly swallowing, noticeable and excessive sweating, a cracking voice, or even a visible pulsing of the arteries in his neck.
👓 How about eye contact? The eyes are the windows of the soul—that’s what they say right? Eyes can certainly provide “tells” when it comes to lying or evasion.
If a person can’t look you in the eye while answering your question that’s a pretty clear indicator something is wrong. But skilled liars—really good ones—know better than to avert their eyes or look down at the floor when answering a police person’s questions.
So it’s better to look for sudden deviations in a person’s eye-contact baseline. Say for instance the witness generally looks up and to the right when answering questions. But then—when asked if they’d ever seen the dead man before—their eyes head left instead of right. That deviation from their previous pattern could indicate a falsehood.
On the verbal end of things . . . again there are tells that should trigger a detective’s internal radar. Some examples:
👓 Is the interviewee’s mood odd or off for the situation? This can include laughing (as O’Leary might say, “who laughs when they are being asked about a body burned in the shape of a crucified Christ?”); excessive swearing; being overly polite; or apologizing without any reason.
👓 Is the witness feigning forgetfulness? Sure, everyone forgets things, but loads of things in a row—things that ought to be sort of unforgettable given the traumatic circumstances? Maybe not.
👓 Is there a noticeable change in the witness’s way of speaking? Has his voice dropped an octave suddenly? Has her rate of speech either speeded up or slowed down dramatically in answering a particular question?
And then there is the “suspicious ‘no.’” Turns out there are a rather stunning number of ways to say “no” that’ll make a police officer’s ears perk up. They include:
👓 A “no” coupled with odd eyes movements—like a witness evading the interviewer’s eyes immediately before giving a negative reply, closing his eyes while saying the word “no,” or delivering a “no” with a completely blank stare.
👓 Mumbling a “no.”
👓 An “off” tone—for example saying “no” defiantly or angrily where those emotions seem out of place.
There are no open-and-shut cases when it comes to tells. No pants on fire. A successful witness interview—like an awful lot of police work—depends on the experience and instinct of the cop doing the interviewing. Deciding what questions to follow up on, what answers sound suspicious . . . that’s a classic case of “go with your gut.”
I’ll close with a bit of trivia—although interviewing suspects is anything but trivial. Question: what is one of the most common mistakes interviewers, including police interviewers, make? (Scroll below the picture for the answer).
Answer: talking too much. Interviews are about listening and perceiving. Additionally, silence can be an interviewer’s friend because a nervous witness may well fill the verbal void—sometimes with “good stuff” they’d otherwise keep to themselves.