As you may well know, polygraph tests aren’t only used in federal cases.  The results that come from the interpretation of the data from a polygraph are also used as evidence to either prove a suspect’s innocence or convict a suspect of a crime.  When a person’s story or involvement in a particular case is doubtful, the authorities can have the suspect take a polygraph test and the data taken from this exam can be used in court proceedings in certain states.

In the US, polygraph testimony is admitted in 19 states.  This all occurred due to stipulation in 2007.  However, it will be at the trial judge’s discretion if the polygraph testimony will be admitted in a specific court case.  Even with 19 states making use of polygraph testimony in court cases, this is still a very controversial subject as it has been determined that there are actually ways in which people can cheat the lie detector machine.  When all it does it monitor a person’s physiological indices like heart rate, a deceptive subject only has to keep calm with every question that the polygraph examiner asks.

There are good days and bad days for the polygraph when it comes to polygraph testimony being admissible in court.  When it was used in the case of Daubert v. Merrell Dow Pharmaceuticals, the results had to be at par with the new Daubert standard.  For cases dealing with sex offenders, polygraphs are still used extensively for determining post conviction supervision.  With regard to enforcement of the law, places like the state of New Mexico allows polygraph testing to be undergone by the subject in front of juries.  In other states, polygraph examiners can testify in hearings in front of judges.

Again, there are select places where polygraph testimonies are admissible in court and there are other places where they’re not.