Another name for lie detector is polygraph and is used to measure and record the pulse, skin conductivity, respiration and blood pressure of a person while being asked questions which are almost familiar. Nowadays most of the companies use lie detectors to engage their employees to know if they are telling the truth to incase of an incident such as theft. When an individual is lying or being dishonest, he or she may sweat too much or avoid eye contact with another person. Examiners of lie detectors can know the quality of truth from the subject’s answers by the response of the body being compared to particular questions. The following are some of the cases or incidents whereby lie detectors are used;
Civil and criminal cases
Hard evidence in civil and criminal related cases is not readily available, or it may not be robust enough to convict the guilty person. The lie detector testing is employed to strengthen the evidence or the witness’ trustworthiness being determined. In most countries, examiners of a polygraph are allowed to give testimony in civil and criminal cases.
Police usually carry out investigations by the use of lie detector to aid them to nail the guilty ones. The test cannot be forced as per the rule of law. The case’s outcome cannot be dictated by the refusal of an individual to carry out the test.
Screening of potential workers
Currently, most of the companies usually conduct pre-employment screening. Jobs opportunities which are considered sensitive in governmental bodies, the candidates must undergo a polygraph test to know whether they are lying or not.
Homeland security related issues
The governmental security agencies such as National Security Agency, Federal Bureau of Investigation, Central Intelligence Service and other bodies which are their primary task is national security, use lie detectors as an established practice. The polygraph test is employed to know what kind threats the country is facing, and also crimes are also uncovered.
Criminal activities in a business
Large firms usually use polygraphs to investigate commercial theft which is occurring or which had happened. Lie detectors are employed by companies which their primary concern is employee theft and fraud. They will be able their workers’ loyalty and honesty towards the firm.
In many countries, the lie detector is used to monitor sex offenders. It is regarded as an established practice for the alleged rapists to undergo lie detector testing before being booked for probation or parole. It is seen as one of the methods or ways of establishing if the wrongdoer has changed or not.