Polygraph testing has been used in many countries for decades and has proven its value as an investigative tool in criminal investigations. The polygraph is a forensic examination that records the physiological changes that take place within the body. Any conscious effort at deception by a rational individual causes involuntary and uncontrollable physiological responses which include measurable reactions in blood pressure, peripheral pulse amplitude, and electrodermal responses. Decades of research has shown that polygraph testing boasts high validity and reliability rates. Through strict adherence to training and education standards, examiners are able to attain accuracy rates of up to 98%, a significantly higher accuracy rate than that of eye witness testimony which research has shown is about as accurate as flipping a coin.
There are many types of polygraph exams and many methods that can be used with the polygraph. One method used is the single testing procedure where one, who has voluntarily agreed to undergo the examination, is asked about a specific incident that they are suspected of doing. This method of testing can assist in narrowing the scope of an investigation very early on by being able to eliminate persons from a pool of suspects and focus investigations on the one that has shown a significantly high probability of deception.
Another method of polygraph testing is known as the Concealed Information Test or Guilty Knowledge Test. This test is different from the aforementioned test, whereas, instead of detecting deception about having committed a specific act per se, concealed information tests aim to detect whether a suspect has information about a crime that only the guilty subject would have. Such information might include details about the site of a crime, the means of which the crime was committed, or the location of a weapon used in a crime. This is an incredibly invaluable test that can be utilized to properly aid in gathering necessary information that may be difficult to determine under normal circumstances.
Additionally, the polygraph examination can be used for pre-employment screenings for persons interested in joining the Security Forces or to hold positions that would require an individual to handle sensitive information. The test would enable the Security Forces and other employing agencies to reject individuals who are not of good character as it reveals much more information than a regular job application form would expose. Furthermore, this allows for the revelation of any deliberate inaccurate statements or pertinent omissions that would prohibit the employer from making a sound decision.
To conclude, it is to be understood that the polygraph is not a panacea for every investigation; however, it has proven to be an effective investigative tool, especially in the absence of other corroborative evidence. The polygraph has significantly enhanced the investigative process for many investigators and Security Agencies around the world. Will St. Kitts and Nevis benefit from this incredible forensic tool? Yes.