The Truth About Catching a Liar

Try these things and watch your prime suspect go red in the face

Among the most troublesome areas of human interaction in which you will have to exercise good judgment and cunning involves being able to tell when someone’s trying to lie or cheat you.

My parents, not so much naive as they were optimistic about other people’s intentions, learned this the hard way in the 1990s when they were shopping around for a bigger house. They found one they liked, but it had an unconventional heating system. Massachusetts winters can be brutal, so they asked the seller whether the electric bills were unusually high.

“Not at all,” came the response.

My parents took this statement at face value and put an offer on the house; it was only after they bought it and began receiving electric bills for $800, $900, and sometimes even over $1,000 per month during the winter that they realized the seller lied.

I never met the seller, so I don’t know whether he was a frequent and effortless liar. Maybe he was generally a very honest man who needed desperately to sell the house. Most likely it was somewhere in between.

Truth be told, the average person lies with some regularity. And they usually experience some degree of guilt about it.

Few people are so gosh-darned principled that they never, or almost never, tell a lie.

Meanwhile, a small fraction of people are incredibly good and bold liars — they lie constantly, maybe even for fun, and the lies come out of their mouths while they’re making eye contact with you and speaking with great confidence and earnest feeling.

May I direct your attention to the political realm for some examples in this third, most egregious category of liars?

Lying politicians are low-hanging fruit, I know, but politics seems to be on everyone’s mind nowadays. And the lies of politicians affect not just individuals and families, but entire countries.

In January 1998, President Bill Clinton lied directly to the camera during a press conference event aimed at quashing the nation’s suspicions over the growing Monica Lewinsky sex scandal.

“I did not have sexual relations with that woman, Miss Lewinsky,” he declared with rock-solid assurance, even though — as the specific details later emerged — he clearly did have sexual relations with her.

The next Democrat in the White House, Barack Obama, had another famous lie, repeated many times on stage in town halls across America as he stumped for the Affordable Care Act during his first term.

“If you like your healthcare, you can keep it,” the President said.

Unfortunately, President Obama repeated some version of this phrase many times despite the red flags being raised by fact checkers, leading to the conclusion that the President was purposefully lying about the impact of his signature legislation. In fact, 4 million Americans lost their healthcare after the Affordable Care Act became law, and some of these later went on record saying they had liked their old plans better.

Neither Clinton nor Obama were able to wriggle their way out of these direct lies when provided with evidence; in both cases they elected to apologize and come clean.

And yet even when challenged directly, some liars are quick to offer an alternative explanation — often an explanation that denies knowledge of any wrongdoing. This blunts the force of the lie by suggesting that everything was just a misunderstanding.

A form of plausible deniability, these lies hinge upon an alternate story to explain the observed statements or behavior. These lies can be tricky to unravel because they often rely on knowing the mindset of individuals at some point in the past.

Like That Time I Lied to the German Transit Police

Lies that can be plausibly denied are sort of like regular lies on steroids.

I’ve written elsewhere about how, when I was in my mid-20s and traveling through Germany, I wanted to see Berlin without having to shell out a hundred euros on transit fees.

Unlike everywhere in America, where access to transit is strictly controlled with gates and meters, Berlin was on the honor system.

Theoretically I could have jumped on trains and buses without ever buying a ticket, but it would have been virtually impossible to talk my way out of trouble if I got caught freeloading.

What I ended up doing was purchasing a day-pass ticket for the Berlin transit system but intentionally failing to validate it.

I knew I was breaking the law, but as a precaution, I developed an alternative explanation, a sort of plausible deniability, for any authorities that confronted me: I’d simply claim that I didn’t understand the validation aspect of the process.

Thus, I reasoned, I could use mass transit for as many days as I wanted for the price of a single day pass, and on the off-chance I was confronted, I would have an excuse.

Well… if you haven’t heard this story before, you might be surprised to learn that everything went well for about the first five minutes.

As it turns out, being an American backpacker on the Berlin U-Bahn automatically makes you an inviting target for the transit police.

Shit hit the fan at Alexanderplatz station, where I was confronted by the police and asked to pay a 50-euro fine for my unvalidated ticket.

Staying true to my predetermined plan, I deployed my plausible excuse and began arguing with the transit police officer over whether I should be punished for my infraction. I lied. I pretended that I didn’t know tickets needed to be validated.

In many cases, claiming ignorance of the law is often no excuse for avoiding punishment.

But in other cases — and maybe the ticket validation issue was one of them — the standard relies on the knowing violation of some rule, edict, or prohibition.

These are hard cases to prove because they require having access to the mindset of the lawbreaker.

My deniability, I guess, was just plausible enough that so long as I lied about my level of knowledge, the German police officer who apprehended me didn’t have the evidence required to take me down to the police station and book me.

Even if he’d found surveillance footage of me reading the fee schedule outside the station, purchasing my ticket, and walking away without validating it, he still wouldn’t have been able to definitely prove that my error was willful because he understandably lacked direct access to my brain.

Getting Them to Confess

To summarize, catching a liar — especially one who has a plausible excuse ready and waiting — is very difficult.

In many cases, the only way to be absolutely sure is to obtain a direct confession.

The most logical way to do this — and this is something I once learned from a homicide detective — is to gather whatever objective evidence you can before questioning a person of interest.

Learn as much as you can about the night in question, the people involved, the technical details of whatever is critical to the deception.

Start by talking to the most objective, least involved sources. Then work your way in, closing in on the suspect and any accomplices using the objective information you have gathered to refine and sharpen your questions for those who most likely have something to hide.

By gathering more objective evidence, you should be able to try to catch your target — who doesn’t know who you’ve spoken with already and what you know — in an easy lie.

Getting back to the example of my parents, they must not have realized that they could simply call the electric company in Massachusetts and request information about the average electric bill for the property.

Armed with this information, my parents could have then either decided not to buy the house at all or else made the same request of the seller to find out whether he would lie.

I imagine the conversation starting the same way, but then veering off much differently thanks to my parents’ superior knowledge:

“Is the electric bill high in the winter?”

“Not at all.”

“So you wouldn’t consider an average monthly electric bill of $800 to be high?”

“Uh… you’re right, I guess that’s kind of high.”

“How about you reduce the price of the house by $20,000 so we can afford to install a standard HVAC system?”

Maybe it would have worked, maybe not.

The point is that the more objective research you do in advance of a potentially fraught exchange, the more opportunity you’ll have to expose deception.

This general tried-and-true approach, by the way, is something that the writers of many TV detective shows often deliberately ignore because it makes the plot more exciting.

Public ignorance of basic investigative techniques is also regularly used to the advantage of public figures embroiled in scandal, who downplay news reports of an investigation by truthfully stating that they have had no discussion with law enforcement about the allegations.

“Nobody from law enforcement has asked to interview me yet,” every politician at the center of a burgeoning scandal always breezily remarks, as though this provides all the evidence necessary to exonerate them.


In addition to this general approach, there are also a few things you can do to cultivate your suspicion and give you the confidence necessary to keep pressing a suspected liar.

The ancient art of reading body language, although not able to prove that someone is lying, can at the very least provide a clue that a something isn’t right. A person who refuses to meet your eyes when talking, a person who crosses their arms and hitches up their shoulders defensively, could be in the process of lying — although you should always do a reality check about whether it’s simply normal behavior for that person.

The way people respond to mild probing questions can also help cultivate your suspicions. For example, I learned from the same homicide detective I mentioned above that anyone who says things like “to be perfectly honest” or “in all truth” could be about to lie. (Again, this doesn’t constitute actual evidence: it’s just something to notice.)

Bombast and exaggeration can be another hallmark of the liar, who compensates for their guilt by protesting too much in the opposite direction.

In response to an imbroglio with Representative Elijah Cummings, a Black man and civil rights leader, President Trump said in July 2019, “I’m the least racist person you’ll find anywhere in the world.”

This use of the superlative “least,” along with the President’s absolute certainty that nobody out there on planet Earth was less racist, almost definitely confirms him as a racistthat is to say, if calling illegal immigrants “animals,” referring to poor nations as “shit-hole countries,” and describing American Nazis as “very fine people” wasn’t already enough evidence.

Yet one more way to raise your suspicion level all the way to DEFCON 2 (DEFCON = Definitely a Con) involves observing how a person reacts when asked to speculate on a suspected misdeed.

A person who has something to hide will often try to “widen the circle of blame” to encompass other people and deflect attention from themselves. By making it seem as though everyone is potentially guilty, the liar thus hopes to evade the sort of microscopic focus that will get them caught.

President Trump’s repeated attempts to cast doubt on Russian election meddling by suggesting that other countries such as Ukraine, Iran, and North Korea were also trying to influence our elections certainly seemed like a big red flag waving out of the White House. By muddying the waters and refusing to focus on the clear and present danger identified by the U.S. intelligence community and members of both parties on Capitol Hill, the President was not-so-subtly widening the circle of blame to distract from his weird affinity for Russia.

I repeat: catching a liar is hard.

And sometimes — maybe most of the time — you will never know whether you were correct.

Is someone deliberately lying? Or did they just misspeak?

Does an excuse sound plausible? Or is it ridiculous?

In the end, as with so much in life, the key is to use good judgment, make a decision about reality, and then get on with it.

I’m more than just a writer. Don’t bother looking for me on Twitter. This is my home at the moment.

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