"Confirming the truth"





Lie Detector New Zealand use the very latest state of the art computerized equipment - the Lafayette LX5000 Data Acquisition System and associated computer software.


This computerized equipment is linked to the instruments that are attached to the examinee’s body on the outside of his/her clothing. Two pneumographs are used to record breathing, one for the thoracic breathing and one for the abdominal breathing; a cardio cuff to record changes in blood pressure and pulse rate; two finger cuffs to record perspiration activity.


Lie Detector New Zealand also use two separate activity sensors to detect any movements made by the examinee which are primarily associated with countermeasures and deception




The figures relating to the accuracy of the Polygraph will vary by a few % points depending on the source of the study but generally it is around 96%.


Reference to the term “accuracy” is misleading. The 96% means that in 96 out 100 tests the results were “Deceptive” or “Truthful”. It is an erroneous perception that the remaining 4% are errors. They are not errors or inaccuracies, they are simply inconclusive results


The Key Question Formulation


A key question is one short direct question which addresses the issue to be resolved. The only answer required by the examinee is “yes” or “no”.




“Since being married have you had sexual intercourse with anyone other than your wife/husband?”


“Since the start of your relationship with (name) have you had sexual intercourse with any other person?”


 “Have you falsified any information on your CV regarding your work history?”


“Have you done anything detrimental to a current or previous employer?”


“Did you cause any of the injuries that resulted in the hospitalisation of (name)?”


“During the last 2 years have you participated in any criminal activity?”


“Did you take any of the money that went missing from the office safe?”


Key Question Process


In each test the key question is asked twice along with 7 other neutral type questions.


The test is repeated 2 more times making a total of 3 tests relating to that same key question. All three tests now form series 1


The process is repeated for additional key questions making series 2 and 3 and 4 etc.


Every question to be asked during a test will be reviewed fully with the examinee prior a test. There are no surprise or trick questions.


Approximate total time for two series is 1.5 hours.



Lie Detector
New Zealand