Polygraph Tests and Effective Investigations

Article Published:Oct 24

Polygraph tests are a popular way to test whether or not someone being questioned is lying. These polygraph machines are used in a wide variety of ways including job interviews as well as criminal investigations. This article will take a slightly closer look at how polygraph machines work and how they can assist in determining who is lying and who is telling the truth.

Generally speaking, when a person undergoes a polygraph test they will typically have between four to six sensors attached to them. These sensors work to monitor breathing rates, blood pressure, perspiration as well as the test subjects pulse. These findings are recorded by using essentially a pen that marks a sheet of paper that is continuously fed through the machine. Should a person be lying, their blood pressure may rise, their pulse may quicken and they may begin to perspire and fidget.

Once the person is properly hooked up to the machine they will be asked a few simple questions that do not pertain to the actual case. These questions are used to ascertain how the subject’s signals would react to a regular everyday question. Following this the polygraph examiner will begin to ask questions relating to the case. The examiner will constantly monitor the machine in order to determine whether or not the subject’s signals suggest that they are lying. The entire session will be recorded so that the examiner will be able further examine the results later on.

Although polygraph tests are usually quite accurate they are not completely definitive. Some people react differently to others when lying, this coupled with the subjectivity of the polygraph tester’s interpretation means that alone the polygraph machine is not conclusive. This, however, doesn’t render it useless. It is often employed in order to gather evidence to add to a case or supplement other findings. For example, eyewitness accounts as well as a failed polygraph test holds more sway in court than just the eyewitnesses’ testimonials.

So while not definitive, polygraph tests do go quite a long way in helping to build solid cases, and also proves useful when screening individuals who are being interviewed. Furthermore, experienced polygraph examiners can often tell whether a person is lying or not with high accuracy. For equipped and experienced private investigators to handle your matter be it employee related, a private or a business related inquest, contact D&K Investigations and Risk Consultancy today!

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