Then why does law enforcement routinely use them? I agree, they aren't conclusive to use in Court, but we aren't at Court. This is merely to aid in investigations. lie detector test.The results are about as unreliable as you can get.
Although the results are usually inadmissible as evidence, lie detector tests can nonetheless be useful in interrogations during criminal investigations. Many confessions have been made after a criminal suspect fails a lie detector test. However, any results of a lie detector test conducted on a criminal defendant that become publicized can be very influential on public opinion of the case, especially if picked up by the news media.
Federal and most state law bans employers in the private sector from requiring employees and prospective employees to submit to a lie detector test. If an employee decides to submit to a test, these laws also prohibit an employer from taking adverse employment action against an employee based upon the results. Some states allow exceptions for embezzlement concerns, in which case the testing procedure is heavily regulated and often monitored. The government may use polygraphs as part of personnel screening for employment, especially for positions dealing with national security.
[Last reviewed in June of 2020 by the Wex Definitions Team ]