Police will use a variety of techniques in an effort to elicit the “truth” from a witness or suspect in regard to the commission of a crime.  One instrument often used-and heavily relied upon by police- is the polygraph examination or lie detector test.  A polygraph instrument is basically a combination of medical devices that are used to monitor changes occurring in the body. As a person is questioned about a certain event or incident, the examiner looks to see how the person’s heart rate, blood pressure, respiratory rate and electro-dermal activity (sweatiness, in this case of the fingers) change in comparison to normal levels. Fluctuations may indicate that person is being deceptive, but exam results are open to interpretation by the examiner. Polygraph examinations are designed to look for significant involuntary responses going on in a person’s body when that person is subjected to stress, such as the stress associated with deception.

Do I have to take a polygraph test if asked by the police?

No.  You can never be compelled to take a polygraph examination by a police officer in the state of Illinois.  It is usually in your best interest not to submit to a polygraph examination because although the results of the examination may not be admitted in court, the results may give law enforcement officials probable cause to obtain a warrant or other judicial order.  Although the Supreme Court has never ruled unequivocally as to the admissibility of polygraph examinations, the Court addressed it in the leading case, United States v. Scheffer. The Court stated, “[t]here is simply no consensus that polygraph evidence is reliable. To this day, the scientific community remains extremely polarized about the reliability of polygraph techniques.”  In light of the Supreme Court’s remarks, trial courts across the country are extremely apprehensive to admit evidence of polygraph examinations.  In some instances, a polygraph examination will only be admitted when both parties stipulate (agree) to submit the results into evidence.

What should I do?

As mentioned earlier, police officers may use a variety of techniques.  A technique that is used in order to have a person submit to a polygraph test is relentless pressure by law enforcement and deception.  Do not underestimate the police!  They can be very persuasive in their attempts to get what they want.  If confronted by law enforcement and asked to submit to a polygraph test, the first thing to do is politely decline.  The second thing to do is immediately contact a qualified Illinois Criminal Defense Attorney.