How does the polygraph as a investigative tool, impact the Homeland Security specialist?Consider issues such as Espionage,Internal crime and Background investigations
A polygraph examination or a " lie detector" test is merely a tool used by law enforcement agencies which has fallen out of favor over the last few years. The results of a polygraph exam are inadmissible in all court's and in all jurisdictions. This means that if you take the exam, and if you were to fail it, that evidence can not be introduced in court. It also can not be introduced if you were to pass it. This is one reason that in criminal cases, the polygraph is essentially useless. Criminal defense lawyers tell you to never, under any circumstances, agree to take a polygraph exam. If you pass it, it means nothing and if you fail it, it means absolutely nothing.
On the other hand, polygraphs are still being used by some employers in conjunction with the background check to "weed out" some applicants. Note that when you apply for employment, the potential employer has to prove nothing. The company may choose not to offer you employment based upon a number of reasons and a unfavorable polygraph result may just tilt the wagon.
Homeland security personnel still use the tool sporadically to either confirm suspicions or to rule someone out. However, not much credence is placed in the test anymore because it is a well known fact that with the correct training, anyone can pass a polygraph examination. This fact renders the tool an ineffective way to conduct an investigation.
Other investigative tools exist like the data voice analyzer. Theoretically, this device senses changes in intonation after being asked probing questions. This is similar to polygraphs because these tests are also inadmissible in court. Critics call this technology "shadow" science, it can not be relied upon to give accurate results.