Often referred to as a “lie detector test,” police officers generally utilize polygraph examinations to assist in their investigations. Although the results from a polygraph are not admissible evidence in court, the police still employ these examinations as a way to get the accused talking.
False Positives and False Negatives
The validity of polygraph exams has always been fairly contentious. When the polygraph is administered, it monitors three indicators: heart-rate/blood pressure, respiration, and skin conductivity. The underlying theory of these exams is that the physiological factors will vary depending if the individual is telling the truth or a lie. Although, there is not a uniform physiological standard if someone tells a lie. For example, someone who is lying during the exam can stay calm while answering the questions versus someone who is telling the truth may have anxiety while undergoing the test. Even the most honest individuals can feel nervous taking the exam due to social anxiety, police presence, and feeling desperation to prove their innocence.
Additionally, certain medications or substances can also thwart the results of a polygraph examination. The Federation of American Scientists reported that the tranquilizer, meprobamate (“Miltown”), causes deceptive individuals to increase their ability to avoid detection during the examination. Other medication such as antianxiety medication and antidepressants can also affect the exam as it reduces anxiety and alter physiological responses.
Polygraph Examiners are Not Required to be Licensed
A new law was passed in September 1, 2021, which removed the licensing requirement for polygraph examiners. Prior to September 1, 2021, a polygraph examiner was required to be licensed through the Texas Department of Licensing and Regulation. The Texas Administration Code Section 88.20, previously required a prospective polygraph examiner to complete an application, complete a polygraph examiner course of study, complete a six (6) month polygraph examiner internship, pass a written and practical examination, and successfully pass a criminal background check. With the Texas Legislature’s decision to deregulate polygraph examiners, the legitimacy of the profession is called into question.
Any Statement or Confession Following a Polygraph is Admissible Evidence
If polygraph examination results are not admissible evidence, why do police officers still use them? Because polygraph exams are a powerful psychological tool law enforcement use to get a suspect talking. Following a polygraph, an individual can feel even more pressure to start talking. Even though the results of the exam are inadmissible in court, any legally obtained statement or confession that follows that exam is admissible evidence. To avoid making any incriminating statements that can be used against you in trial, you must consult with a criminal defense attorney to discuss your options.
Contact an Expert in Criminal Law
If you or someone you love is currently being investigated for a crime in the Greater Houston area and beyond, you need to speak to an experienced criminal defense attorney before consenting to a polygraph examination. If you consent to a polygraph examination and you ultimately fail it, there is little that you can do to convince the police or the prosecutor that you are innocent. Scheiner Law Group, P.C., is an excellent choice to defend you and advise you prior to speaking with law enforcement. Call us during normal business hours at (713) 783-8998. After hours and on weekends, text (713) 581-4540.