Should I Take a Lie Detector Test Offered By the Police?

In serious criminal investigations, such as criminal sexual conduct and murder cases, it is not unusual for police to ask a suspect to take a polygraph examination, otherwise known as a lie detector test. In doing so, the police are not looking to eliminate a suspect or get to the truth; they are trying to use the polygraph as a tool to elicit a confession from the suspect. It is rare that the police even care about the actual results of the test for purposes of their investigation.

Polygraph examination results are not admissible in court for criminal cases. This is because lie detector tests are not scientifically reliable. There is no evidence to support that there is any pattern of physiological reactions that are unique to deception. Because different people have different physiological reactions to different situations (e.g. a truthful person may be nervous when answering truthfully, and a deceptive person may be calm when telling a lie), it is impossible to conduct a proper validity study. Because the scientific reliability of these tests cannot be shown, the courts have determined that they are not admissible as evidence in court.

Many times, the police will have a suspect appear for a polygraph examination, and regardless of the actual results, will tell the suspect that they have failed the polygraph examination. They will use the assertion that the suspect failed the polygraph in order to try to get the suspect to confess wrongdoing. If the suspect continues to deny that they committed the crime, the police will tell the suspect that the polygraph machine doesn’t lie. They will continue to place pressure on a suspect to confess, or try to get the suspect to start speculating about why they might have failed in order to get them to make harmful statements that they can use against them later.

Generally, attorneys for a suspect are not permitted to be present during the administration of the polygraph examination, including the interrogation portion. The police want to isolate the suspect and use the test environment to break the suspect down, resulting in a confession.

If you are currently a suspect in a criminal investigation, and the police have asked you to take a polygraph examination, you should not agree to submit to a test. Many people believe that they will simply be able to go in and clear themselves by taking the lie detector test. The truth is, however, that most police polygraph examiners will not be interested in whether or not you are actually telling the truth.

If you have been asked to take a polygraph by a police officer, or maybe have even scheduled an examination, you should either cancel the examination or hire an attorney to represent you who can communicate to the police officer that you are not going to be taking the polygraph.

While there are no absolutes, it is almost never advisable to take a police polygraph. There are some extremely limited circumstances under which you might consider doing so, but you should not do so without first consulting with a lawyer who is very experienced in dealing with polygraph examinations in relationship to criminal investigations.

This doesn’t mean that a polygraph examination can’t be useful in your case. You have the option to take a private polygraph examination with an examiner who is hired by your attorney. This is appropriate in some cases, while in others it is not. In order to determine whether or not you should take a private polygraph examination, you should consult closely with the attorney who is representing you in the criminal investigation.

The lawyers at Blanchard Law have extensive experience in issues involving polygraph examinations in the context of criminal investigations. If we can help in your case, please don’t hesitate to give us a call.