Lie Detector Test Definition and Legal Meaning

On this page, you'll find the legal definition and meaning of Lie Detector Test, written in plain English, along with examples of how it is used.

What is Lie Detector Test?

(n) Lie Detector Test is the polygraph test which adopt the technique of measuring the psychological reaction in a body when a person tells a lie or conceal a fact, there by judging the authenticity of answers made by the person subjected to the test. It is a matter of mental strength, so a seasoned liar may go scot-free in this test

History and Meaning of Lie Detector Test

The Lie Detector Test, also known as the polygraph test, was invented in 1921 by John Augustus Larson, a medical student and police officer from California. The original machine that Larson created was improved upon by Leonard Keeler, and since then, the test has become widely known as a tool to determine whether someone is telling the truth or lying.

The basic principle of the Lie Detector Test is that when someone tells a lie, their body gives off certain involuntary physical reactions. These reactions, such as changes in heart rate, blood pressure, and perspiration, can be measured and recorded using the polygraph machine, making it possible to differentiate between truthful and deceptive answers.

Examples of Lie Detector Test

  1. The police used a Lie Detector Test on the suspect to determine whether or not he was involved in the crime.
  2. The job interview for the government agency required candidates to take a Lie Detector Test as part of the screening process.
  3. The celebrity guest on the talk show agreed to take a Lie Detector Test to prove their innocence in a controversial situation.
  4. The defendant in a high-profile criminal case requested a Lie Detector Test to prove their innocence to the jury.
  5. The company conducted Lie Detector Tests on their employees suspected of stealing company property.

Legal Terms Similar to Lie Detector Test

  1. Polygraph Evidence - Refers to the results of a Lie Detector Test, and is frequently used by law enforcement agencies in their investigations.
  2. Admissibility - Describes whether or not evidence, including polygraph evidence, is permitted to be presented in court.
  3. Expert Witness - A person who possesses specialized knowledge, skill, or experience that is recognized by the court as being reliable and relevant, and who is called to testify in a legal case.