There are many such tests in medical science, by which almost everything can be known about a person. Polygraph test is done to know whether a person is speaking the truth or a lie. In Kolkata, six people including Sanjay Roy, accused in the rape-murder case of a trainee doctor, will undergo polygraph test. But do you know that the court does not consider the report of polygraph test as valid? Today we will tell you how a polygraph test is conducted.
what is a polygraph test
Now first of all let us know what is a polygraph test. Let us tell you that the lie detector machine is called a polygraph machine, it detects whether a person is speaking the truth or a lie. It looks like an ECG machine. Now you must be thinking how is this so? Actually the polygraph test is based on the belief that when someone is lying, there is a change in heartbeat, breathing, sweating. During interrogation, devices like cardio-cuff or sensitive electrodes are connected to the person and BP, pulse etc. are measured.
When was this machine started
According to information, such a test was first conducted by Italian criminologist Cesare Lombroso in the 19th century. He used a machine to measure changes in the BP of criminal suspects during interrogation. A similar machine was later created by American psychologist William Marston in 1914 and California police officer John Larson in 1921.
Is consent necessary for polygraph test?
Now the question is, can any investigation agency conduct a test on any person? The answer is no. Actually, the consent of the accused is necessary for a polygraph test. If the accused does not give consent, then the security agencies cannot force him to undergo a polygraph test. But usually the accused agree to undergo a polygraph test to prove himself innocent. Many times the accused agree to undergo a polygraph test to prove himself right in the court.
This test is not valid in court
Due to many reasons, polygraph test and narco test have not been scientifically proven to be 100% successful. However, investigative agencies give them priority. Perhaps it helps them in gathering evidence. No court accepts the report of polygraph test, although the court considers any statement made by the accused during interrogation in polygraph test as valid.
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