Can We Make the Defendant Take a Polygraph and Use that as Proof?

I’m Katelyn Holub, an attorney focusing on personal injury law in northwest Indiana.

Welcome to Personal Injury Primer, where we break down the law into simple terms, provide legal tips, and discuss topics related to personal injury law.

Today’s question comes from a caller who says “I want to sue my neighbor for backing into my parked car, I know he did it, even though I have no evidence, can’t we just make him take a polygraph, and use that as proof?”

Great question. Unfortunately, the answer is no.

TV legal drama programs often use lie detectors. Federal agents must in certain internal security matters submit to polygraphs.

But, in most civil case situations you cannot make someone take a polygraph. Under some employment contract situations, such as high security businesses, people, as a condition of employment, agree to submit to lie detectors, and agree that employment decisions can be made using test results.

Let’s explore why courts don’t rely on and allow polygraph results to be admitted into evidence.

The prime reason is that the lie detector can’t really reliably tell a truth from a lie. And if you (the person being questioned) truly believe something to be true, even if it’s been wholly fabricated, the lie detector will in fact shows signs of you being truthful.

Here’s why…a polygraph (although deemed up to 85% accurate by certain studies) has no real capacity for telling if a statement is the truth or is false – the device simply measures biological processes such as blood pressure and heart rate.

When hooked up to a lie detector, sensors are placed on your fingers, chest and even your forehead which monitor your body’s response to certain questions.

Usually the test operator starts off with basic questions such as asking your name, where you live, your occupation. These questions are supposed to create a baseline, which then will be used to compare to the responses of additional questions.

Then the test operator asks some challenging questions, ones that are designed to get you to review detailed answers or create confusion with your replies.

When the needle measuring your response goes wild, the operator makes a note on the readings indicating maybe you lied, or you just felt pressured or that you were just nervous.

The machine will record your nervousness or sweating or even the temperature change of your skin.

Does that mean you lied? Maybe you were nervous being hooked up to a machine or being scrutinized in that fashion … and now you’re tagged as guilty of a lie. See the problem?

And, if your memory has been manipulated, nothing you say will be a lie so your blood pressure or heart rate will not spike. Now you’re probably thinking… “manipulated”? How can someone be “manipulated”?

Memory is pliable, memories can be altered, details added later and some events fabricated.

People under hypnosis, for example, can be implanted with false memories. And they recall events as if they were there in that moment, yet the event never really happened. And people who suffer traumatic experiences (injuries, assaults, accidents, war) may create false memories to protect themselves, to shield themselves from remembering what actually happened.

If it came down to memory recall the person who was able to share the more vivid, more detailed memories would garner the more favorable result … a win.

It gets worse. In a newspaper commentary in 2018, a writer pointed to a study where it was relatively easy to “implant” false memories in a significant number of lab subjects by showing them an official-looking poster of Disney characters, including Mickey Mouse and Bugs Bunny.

When questioned later, many subjects remembered meeting Bugs Bunny on a childhood trip to Disneyland. Some even reported that Bugs had touched them inappropriately. … Here it comes … that memory could not possibly be legitimate. Bugs Bunny is not a Disney character.

If Lawyers, Judges or Juries were to make decisions based solely on the recall of someone’s memory, the one who remembers the most would win every time regardless of if their statements were really the truth.

This is why evidence is so important (by that I mean physical evidence like footprints, DNA, fingerprints). Physical evidence tells us what happened better than our memories.

I hope you found this information helpful. If you have questions about your legal rights if you get hurt due to the carelessness of another person, or as a result of substandard medical care, or due to a product defect, construction injury, or any other type of personal injury, please give us a call at (219) 736-9700. You can also learn more about us by visiting our website at www.DavidHolubLaw.com – while there make sure you request a copy of our book “Fighting for Truth”.