retcopper wrote on Mar 24
th, 2006 at 4:35pm:
1. Polygraphed a subject who denied shaking an infant and killing him. He failed my poly and gave me a confession. Hold up man shot and killed two customers, failed my exam and gave a confession and two other homicides are solved.
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Listen - few reasonable people would question the effectiveness of the polygraph as an interrogative tool. I agree it can be tremendously useful when used as part (not all) of an investigation - particularly on ignorant thugs who couldn't tell the difference between an fMRI and a colander (see below).
No question: the polygraph community has successfully built up this unflappable mythos that polygraphs somehow transcend the human mind to get to the truth. We all know that's not the case. The polygraph works best when the party being polygraphed believes it works best. If the examiners who browse this site disagree with that, you're either fools or facetious.
That said, I agree the polygraph has a place in society. I'm realistic enough to realize that the polygraph community, top to bottom, is a multimillion dollar one - from the equipment, to the schools, to the lucrative government work. This profession, like any other, puts food in mouths, and is a source of pride for the many folks who practice it.
But it's important to make sure that the poly's role in society is a limited one - one where 1) its use is "incident-specific" - for example, crimes where the GKT (which is less flawed than the CQT) can be used. And where 2) the benefit of passing is equal in weight to the potential harm of failing. In the criminal context, this is generally the case: if you pass, you're not exactly exonerated - the investigation continues if you're a suspect. If you fail, the information is inadmissible.
Use of the polygraph in a pre-employment screening situation is a gross misjudgment on the part of the government, however. Passing means the background check continues - you gain little of value other than continuing in the security screening. Failing, however, in many cases means a lifetime ban from reapplying with the agency (often incongruous with the agency's own screening policies), and sometimes a compete ban from sensitive gov't work. This is also the case for current gov't employees. You pass, you keep your job. Fail, and your career is effectively over.