A polygraph lie detector test is an exam that uses a device to record various electrical signals and physiological indicators to try and determine whether an individual is lying or not. The device picks up on certain bodily changes, such as a spike in blood pressure or pulse, perspiration, and other involuntary changes that may indicate a person is lying. Non-harmful electric nodes are attached to the skin while a person answers a set of specific questions.

A needle records the person’s bodily changes as they answer the questions. At the end of the session, experts will review the report that the needle recorded to make their findings. The assumption is that when a person lies in response to a question, their body will exhibit certain physiological responses that cannot be concealed by lying. 

In the past, these tests were often administered on witnesses or suspects as a way to advance police work and support criminal investigations. They were also used by government agents and attorneys in order to interrogate suspected criminals. Eventually, polygraph tests were even used by employers to determine whether a job applicant or employee was lying. 

More recently, however, experts have advised against using such exams for any reason since the accuracy and reliability of their results have come into question. This is due to the fact that the physiological indicators for lying are frequently conflated with factors that exhibit nervousness, excitement, anxiety, and so forth. 

Obviously, emotions like excitement or nervousness are not necessarily indicators that a person is guilty. It just means that the individual may feel stressed or extra pressure, which is understandable, given the conditions of their situation. 

One final important item of note about polygraph tests is that no one may be forced to submit to a polygraph test against their will. In other words, polygraph tests cannot be administered without notice and without an individual’s consent. Part of the reason this protection exists is because of a federal polygraph law that was passed by Congress in 1988 known as, “The Employee Polygraph Protection Act (“EPPA”)”. 

The EPPA prohibits most private employers from using these tests for either job applicants or current employees. Employers may also not take any actions towards an employee (e.g., terminating, discriminating, disciplining, etc.) for refusing to take a test under the Act. The same holds true about law enforcement. Again, you cannot be pressured to submit to a polygraph test and your refusal cannot be used against you as evidence in court. 

Therefore, if you are having issues that involve taking a polygraph test or with the results of your exam, then you should contact a criminal defense attorney immediately for further legal guidance.

Are Polygraphs Admissible in Court?

Whether a polygraph test is admissible in court will depend on the jurisdiction. For instance, polygraph admissibility by state varies widely. However, they can generally be divided into two main categories: states that find the results of the test entirely inadmissible, and those that allow them in court, but only if it is submitted with stipulations from the parties. In other words, the latter category requires that both the suspect and prosecutor must agree to admit the results.

As of today, 23 states still consider polygraph tests to be admissible in court. However, the majority of those states require the approval of both parties before they can be submitted. Also, in most cases, the polygraph test is not being used in a criminal case, but rather in civil court, such as if there was an issue that prevented a person from getting a job or gaining security clearance. 

For example, in the state of Georgia, a defendant who suffers harm due to a false result on a polygraph test may sue the polygraph test administrator for damages and attorneys’ fees. So, if a private individual lost out on a job opportunity in Georgia because a test administrator read the results wrong or asked inappropriate questions that flustered the individual and caused them to fail the test, they can sue that administrator for monetary damages.

On the other hand, there are some states that find polygraph tests completely inadmissible, even if both parties consent to their use. These states include New York, Texas, Pennsylvania, Illinois, and the nation’s capital, Washington, D.C. 

The reason as to why states are so split on this issue is because aside from the EPPA, there are no uniform standards that apply and it is mostly up to the discretion of the judge and/or state laws. For example, initially the idea of court cases using polygraph tests as a reliable form of evidence was struck down in the seminal case of Frye v. U.S. in 1923. 

Over time, new Federal Rules of Evidence (“FRE”) were passed and soon federal judges were given more discretion over admissibility. In the 1993 U.S. Supreme Court decision of Daubert v. Merrell Dow Pharmaceuticals, which for the most part replaced the Frye test, the Supreme Court ruled that such evidence could be accepted if it satisfied the five factors of the Daubert standard.

More recently, in the 1998 case of U.S. v. Scheffer, the U.S. Supreme Court issued an opinion, stating that polygraphs did not need to be admitted as evidence in military trials unless a judge granted permission to do so in accordance with the Daubert standard.

Finally, as mentioned, the EPPA was passed in 1998. This Act currently still applies to many civil court cases concerning polygraphs and employment issues. However, it does not apply to government workers (e.g., federal, state, and local government agencies), or those being hired by security firms or pharmaceutical companies. The Act also provides separate definitions for “lie detector” and “polygraph”, and lays out what is prohibited under federal law. 

When Are Polygraphs not Admissible in Court?

Polygraphs are not admissible in court when either the state does not recognize them as valid exams, when both parties do not stipulate to allow them into evidence in states that do permit them, when the law prohibits their use in certain situations, and/or when a judge refuses their admittance in a specific case. 

As previously mentioned, this is because experts and other parties have agreed at this point that the results of this test are not very reliable. There may be defects in the device used to record the test results, or there may be inherent bias in the person administering the questions or test. Overall, they tend to provide inconsistent responses due to physiological indicators that imply one or more emotions other than guilt.

In addition, because there are other ways to find evidence that do a better job of supporting a prosecutor’s arguments, they are really only used as a last resort in the states that permit them and they are not considered the strongest form of evidence.

There has also been speculation that law enforcement has previously abused the application of these exams as an investigative tool. For instance, this might happen by prolonging the amount of time a test is held for to wear down and obtain a confession from a suspect. In such instances, law enforcement is said to be violating a person’s constitutional rights, which is illegal.  

If I Am Arrested for a Crime, Can I Be Forced to Take a Polygraph Test?

As discussed above, both the EPPA and other state laws make it illegal to force a person to take a polygraph lie detector test. However, if the person voluntarily agrees to take one, this evidence can be used against them in court.  

Also, if a suspect refuses to take a lie detector test, this fact cannot be used against them in court. There is absolutely no legal obligation that says an individual must undergo a test, even if law enforcement attempts to pressure them into taking one.  

Lastly, it should be noted that even if a court refuses to admit the results of the exam as evidence, a prosecutor can still use a final report to support their case against the defendant. Thus, if someone is trying to coerce a suspect into taking a polygraph test, they should contact a criminal law attorney immediately to protect their constitutional rights. 

Can I Take a Lie Detector Test to Prove My Innocence?

Although it is generally not recommended, an individual may request to take a polygraph to prove their innocence. However, it is important to remember that these exams are not the most reliable form of evidence. In other words, someone who is innocent can still appear to be lying on these tests due to nervousness or anxiety. Law enforcement and/or the prosecutor can then use these results against the individual if they voluntarily submitted to it.  

On the other hand, a person who is not innocent may be able to pass a polygraph test. Regardless of the outcome, law enforcement and the prosecutor can find other evidence that supports a guilty verdict. If they do find other evidence, having a lie detector result that shows a person “beat it” despite all the evidence against them, may imply that they are a disreputable person.  

The prosecutor can use this fact as more evidence against the defendant if the defendant introduces the results to prove they are innocent at trial, which may then end up hurting their case rather than helping it. 

Do I Need a Lawyer for Help with Polygraph Test Issues?

The laws and issues surrounding polygraph tests can often be difficult to understand without the help of a lawyer. Each jurisdiction also has different procedural requirements for taking polygraph tests and interpreting their results. They may also have various clauses in their regulations that do not apply in every state. 

Therefore, if you have any questions or issues regarding a polygraph test, then you should speak to a local criminal defense attorney as soon as possible.  

An experienced criminal defense attorney will be able to discuss the results of your test and can explain what they might mean for your case. Your attorney can also inform you of your rights as a criminal defendant, discuss your potential legal options (e.g., plea deal, go to trial, etc.), and provide representation in court if necessary.