Matthew J. Ruff

The question of whether one should take a polygraph or lie detector test is one asked of many people suspected by the police of committing a criminal offense.  Often, a law enforcement investigator or police detective will ask a suspect to submit to a polygraph test in order to "get their side of the story".  In my experience, having been a criminal defense attorney for well over a decade and having personally handled well over two thousand cases, the police usually use the request to submit to a polygraph as a ruse to simply question the individual in a controlled setting.  The purpose is not to get to the "truth" or determine whether the person is lying, the office usually already knows that.  Having an individual take a lie detector test allows statements to be obtained and permits the detective to lock the person in to a particular story.

Most experienced criminal defense lawyers and other professionals, including judges,  will advise a client to not take a polygraph at the request of police.  Instead, the detective should be asked to allow the suspect, through his or her attorney, to choose an independent polygrapher  and conduct their own test and submit the results to the police.   This is preferred because it gives the attorney control over the manner of the testing and ultimate reliability. 

Another option is to request that the results be admissible in Court through a stipulation of the criminal defense Lawyer and the local District Attorney.  The bottom line is they will usually not agree to these terms  but it gives the criminal suspect a polite "out" to refuse to submission of the polygraph.

The machines themselves are not known to be reliable and therefore are not otherwise admissible in a criminal case.  The devices are subject to manipulation by the examiner and are very subjective in terms of the results.  A polygraph machine can be manipulated by artful questioning and careful preparation of the subject.  A criminal defense lawyer  familiar with all the issues should be retained immediately if a person has been alleged to have committed a criminal offense.

The pros and cons of submitting to a polygraph should be discussed with the individual's criminal defense attorney.