Polygraph is informally referred to as lie detector tests. Most courts refuse to admit results of polygraph tests, saying that scientific evidence has not yet produced a proven reliability of such test. A court within its discretion may allow the use of polygraph tests, but such cases are very infrequent. Courts have repeatedly ruled on the admissibility of “scientific evidence” (such as DNA fingerprinting).
The appellate courts have ruled in different ways. Regardless of the outcome, the case throws into sharp relief the argument over the quality of science heard in the courtroom. Rules of evidence change. In recent years the courts have allowed evidence of some scientific tests or experiments to be admissible in evidence if these scientific tests or experiments show that certain facts are true. For example, some courts have held that DNA tests are 100 percent reliable; others still hold DNA test results unreliable and inadmissible.
The modern method of recording the physiological activity of liars is associated with the use of a polygraph. The name “polygraph” comes from two Greek words – “poly” (many) and “grafo” (write). This scientific measuring device can make accurate and valid recording by means of an ink recorder on chart paper or images of various types of physical activity on a computer display.The most commonly measured parameters are sweating of the palms, blood pressure and respiration.
The Advantages Of The Polygraph
The main advantage of a polygraph survey is efficiency. After a crime has occurred, it is almost impossible to carry out complete operational search activities. It is necessary to “work out” several people, i.e. follow, listen, interrogate several times, establish a circle of acquaintances, etc., all this takes a lot of time and money, while a polygraph survey takes about 2 hours per person. Thus, in a few days you can interview all the suspects and avoid the of people who are not involved in the crime.
An honest person has nothing to hide. If you did not commit actions that leads to a crime, then you have nothing to worry about. Behave correctly with a specialist,your aggressive behavior will cause him to increase his vigilance .This may indirectly or directly affect his conclusions when he decides on your innocence or guilt.Sometimes a polygraph is called a lie detector, but this term is misleading.
The polygraph does not reveal a lie, but only arousal, which may be the result of telling lies. There is no other way to detect falsehood except indirectly.People who talk about the uselessness of a polygraph and those who believe its endless possibilities are equally mistaken. They need to keep in mind a polygraph has its advantages, disadvantages, and limits of application.