East Lansing Criminal Defense and Polygraph Exams AKA Lie Detector Tests

How a Polygraph Exam Can Be Used to Clear an Innocent Person


A polygraph is generally known by its commonly used nickname, the “lie detector” test. Most people have never really taken the time to understand how one of these machines work, and what it actually measures. Before starting, an individual will be connected to the machine through a series of sensors that are attached to different parts of his or her body. A polygraph measures several physiological indicators of an individual while they answer a specific series of questions. The physiological indicators that a polygraph measures include blood pressure, pulse rate, respiration rate, and skin conductivity. A polygraph exam will typically begin with a pre-test interview which will help the examiner formulate the relevant questions for an exam. These questions will then be asked along with simple unrelated questions and the answers and physiological reactions to the answers are recorded. The examiner will then make a determination from an individual’s physiological responses to the questions asked whether they are being deceptive or not. The idea behind measuring these indicators is that someone who answers questions deceptively will conceivably have different physiological responses than when answering questions without deception. While the accuracy of polygraph exams is still precisely unknown, polygraph exams are extensively used in criminal investigations in the United States as it is estimated that 2.5 million polygraph exams are administered yearly. 


In the case of United States v. Scheffer, the Supreme Court ruled to allow individual states to determine the admissibility of polygraph exam results. In Michigan, the case of People v. Barbara and citing cases thereafter generally excluded the results of polygraph exams from being introduced at trial. There is, however, no per se rule in Michigan barring the introduction of polygraph exam results or the testimony of a qualified polygraph examiner. Michigan courts have admitted polygraph test results in certain situations. People v. McKinney and People v. Mechura are two examples of Michigan cases that have allowed the introduction of polygraph exam results at trial. It is important to note that if you take a police polygraph, what you say and how you acted in that polygraph exam is just as admissible as any other statement made to police not administering a polygraph exam. The main issue here is admissibility of the results and the testimony of the polygraph examiner to potentially help aid in your defense proclaiming your innocence. While people often fail polygraph exams, what happens if you pass one? Does that mean that the prosecutor’s office will dismiss the charges against you? The unfortunate answer to that question is that it depends. It is recommended you speak to an experienced criminal defense attorney who can best answer your specific legal questions.


The technology and science behind polygraph examinations has greatly improved in the nearly 100 years since the inception of the machine back in 1921. If you are successful in getting the results of a polygraph admitted at trial, then you will be able to have the polygraph examiner explain how the test was administered, discuss your results from the test, and give his expert opinion on the deceptiveness or truthfulness of your answers. A polygraph examination can be administered by the police or by a private company. If you take a polygraph exam with the police, then your statements can still be used against you since you are answering police questioning. If you take a polygraph examination with a private company, the discussion and results of that exam will be kept completely private unless you decide to give the information to the prosecution. Depending on the questioning conducted during a polygraph exam and the amount of trust a given prosecutor has with a given polygraph examiner, a passed polygraph exam can possibly result in a dismissal of your criminal charges or can also result in you never being charged at all. If you are curious about taking a polygraph exam and wondering if the results may be beneficial to your defense, then call us at Oakes Law Group today so we can help. 


If you have one or more convictions on your criminal record that you are looking to expunge, then it is important to speak to an experienced criminal defense attorney immediately. At Oakes Law Group, we are proud to offer FREE consultations to all prospective clients. If you are in the process of choosing your attorney or are looking for an honest assessment of your legal situation, then our attorneys are available to help you now. Feel free to contact us anytime at 1-888-886-5711 or email. Our advice is free, and our conversations will always be protected by attorney-client privilege. Make your first choice towards a clean record with a consultation with an experienced criminal defense attorney at Oakes Law Group today.

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