Walsh Polygraph & Background Investigations

 

Are polygraphs accurate/do they work?

Polygraph tests have been shown in research studies for decades to be exceptionally good at detecting deception/verifying truth. A 2011 meta-analysis by the American Polygraph Association showed that techniques which were stringently researched and validated, and used by trained examiners, were routinely accurate in 90% of deceptive cases and 85% of truthful cases. When examiners use the phrase "It is 85%-90% accurate," it means that 85%-90% of the tests administered are 100% accurate. It also mean that the other 10%-15% of the time- it is inaccurate or an opinion cannot be rendered.

 

There have been problems with the profession in the past; however, those problems stemmed from the examiners, not the instrument or science behind it.

 

Does nervousness cause a subject to fail?

Every person who enters a polygraph office is nervous; that factor is irrelevant. The charts are evaluated for specific criteria, based on the decades of research that determined the typical responses of deception and truth. Nervousness is not one of the criteria.

 

How long does a polygraph examination take?

Polygraph exams, conducted properly by a trained, experienced, and educated examiner, rarely take less than 90 minutes. There are procedures in place to ensure that the examinee has enough time to ask any questions, get comfortable with the process, and collect the best possible data.

 

Can the polygraph be wrong?

Yes. While the polygraph is extremely accurate, it is not perfect and errors do occur, as they do with any test. The error can be due to the examiner’s failure to prepare the examinee properly, failure to accurately evaluate the polygraph charts, or it can be the very rare occurrence of a false positive or false negative. Examiners employ several procedures to mitigate the factors that cause an error. As with any test, the examiner can do everything right and still have the test result in an error. Additionally, polygraph has an inconclusive rate of 5%-15% depending on the technique used. Polygraph examiners should have their polygraph examinations quality controlled when possible.

 

Many of the criticisms of polygraph stem from “screening” exams which are broad in nature and lack in specificity. This leads to a slightly lower accuracy rate and a higher number of inconclusive results. In exams which are specific issue, as most criminal cases are, the accuracy rate is greater than 90%.

 

What is a polygraph?

The polygraph instrument records reactions to stimulus. The polygraph components consist of pneumo tubes around the chest and abdomen which record respiratory activity, electrodes on two fingertips which record skin conductance (or resistance), a blood pressure cuff placed on a bicep or forearm which records relative blood pressure, and a plethysmograph, placed on a finger, which records blood volume.

 

How many topics can be covered?

For specific issue testing, no more than two or three specific topics can be covered. The questions must be formulated to have “yes” or “no” answers, and the best questions address a specific physical action. Knowledge and intent are more difficult to test. In short, “Did you….? is the best way to use polygraph.

 

Is polygraph admissible in court?

(from the American Polygraph Association website)

Polygraph admissibility varies from jurisdiction to jurisdiction. Some states ban it completely; others allow results by stipulation; and some allow polygraph evidence over objection.

 

https://www.polygraph.org/polygraph-frequently-asked-questions

 

If you have any further questions, please feel free to reach out, I am more than happy to answer any questions and make all parties feel confident in the examination. I’m enthusiastic about polygraph and any familiarization I can provide.