Polygraphs or lie detectors are technical devices that are used as a popular took among U.S. law enforcement agencies for determining deceit. The first lie detector was utilized in 1895, and the polygraph that is now used in court was developed in 1926. Both the polygraph and the lie detector have been used in trials all throughout the United States. The Supreme Court has deferred judgment to the courts of each jurisdiction to determine whether or not the exam results of a polygraph are admissible evidence in court.

This means that you will want to determine whether or not polygraphs are approved in your jurisdiction if you are asked to take a test with one of these machines. Unfortunately, polygraphs are not always correct. They can merely sense the body language and responses of a person who may or may not be telling the truth. A very nervous innocent may give off a similar demeanor as a guilty individual, so the results of the polygraph should never be the determining factor in any case.

According to EHow, the function of the polygraph is that it collects physiological data such as respiratory activity and processes that to determine whether or not the person may be lying. The polygraph also determines a person's sweat gland activity and cardiovascular activity. Polygraphs are based on the idea that a person that is lying will experience these physiological, involuntary changes in blood pressure and body temperature.

There may also be changes in skin conductivity and a person's pulse or respiration. If you experience these symptoms and are innocent, then a polygraph could actually lead to a false accusation, so you will want to be extremely cautious to determine the difficulties of your case and check to see how a polygraph will affect your defense. As a general rule, polygraphs are popular and are used with federal, state, and local law enforcement agencies to determine whether or not a person committed a crime. The Employee Polygraph Protection Act of 1988 can protect and prevent employers from requiring applicants and employees to undergo polygraph evaluations, so if you are being accused of a work related offense you may want to check into how this affects you.

The U.S Code and the Federal Rules of Evidence both do not discuss polygraph examination results. Therefore it is not determined whether or not the polygraph should be used in regards to this level. The U.S. Court has deferred judgment to the courts of each jurisdiction to determine whether or not the polygraph exam results are admissible. This means that some federal circuits won't allow a polygraph exam as evidence, but others will. In all jurisdictions, an individual must agree to the admissibility before the exam is given. This means that if you refused to allow the exam to be used as evidence in court, law enforcement cannot dishonor your request and submit the evidence anyway.

The states of Nevada, Arizona, California and Florida all permit the use of the lie-detector in court if all parties agree beforehand that they will be admissible. In states like Texas, New York, Pennsylvania, Illinois, and the District of Columbia, no polygraph results are permitted. If you live in one of these states and polygraph results are a factor in your case, you will want to discuss your concern with an attorney who will make sure that state policy is followed regarding these tests. In Massachusetts, the exam results can be used as evidence but they cannot be used by police as a means to obtain a search warrant. Other states have specific laws regarding the use of polygraphs for certain crimes. In Florida, sex offenders is required to undergo a polygraph examination but the test results are only for rehabilitation and treatment and cannot be used as a means to prosecute or prove a point in court. If you want more information about the polygraph laws in your state, then a local attorney can help