Can you rely on the quality of Truth Verification tests?

Quality of Truth Verification tests.

Today again I had a client phoning me regarding a truth verification test that was done by an “expert” and the client doubted the results.

The examiner tested 22 people (in one day) and found 18 to show deception. The client wanted to know how if they can rely on the results.

As a rule of thumb, a screening test should take at least 90 min (1h30m). An incident investigation, (zone) test will take between 15–60 minutes longer than a screening as there are issues to discuss before the test can be done. A zone test should only test for a single issue. If there are more than one issue to be tested, a separate zone test should be conducted thus adding about an hour to the testing time.

Polygraph testing should take longer than voice stress testing as the polygraph examiner have to unpack and set up a lot more equipment. The polygraph testing process is also significant longer than voice stress and therefor the higher price for polygraph testing.

We very seldom test less than 2 hours on any type of test.
Our longest test to date was 21 hours over a period of 3 days (murder investigation) and consisted of 27 tests ranging from screenings, zone testing, WET and POT tests to get the final result.

As the client, you should first look at the test duration of about 2 hours per person to get an accurate and reliable test result you can work with. If anything less, you could sit with a red face in the CCMA and labour court and spend a lot of unnecessary money on legal issues that could have been avoided. The duration of the pre-test phase and the in-test phase is determined by the examiner and should not take less than 90 minutes but the duration of the discussion of the incident is determined by the person being tested this can vary depending on how much they want to talk.

If a person test DI (Deception Indicated), the examiner is supposed to try to get a reason for the fail and if possible at all a confession to go with his/her DI result.
The quality of an examiner is measured by their confession rate on the DI tests and not by the quantity of tests they can do in one day. If they have a high confession rate, you can be assured that they followed the correct procedures.

Some Security Companies want “quick and cheap” tests on their staff and the result of all these results should state “NDI (no deception indicated)” as they want to show this to their clients in an attempt to avoid responsibility in case of an incident. This is called window dressing and degrades the Truth Verification industry. All examiners doing this should be reported and the client should insist on an external examiner .

Be careful of “cheap” tests and examiners that can test the same day or the next day as this is an indicator that they have no work booked. In principal, the more expensive the tests are and the longer you need to wait for the examiner the better (that is if you want an accurate result).

I trust this will assist in selecting a professional examiner to test for you.

Chris Nel
APAVSA Instructor on Voice stress, Polygraph and Poly-Stress (Africa & Australia)